Rapid LINUX / UNIX solutions

Windows not sycing with NTP server

2012-01-30T11:40:00.000-08:00

NTP (Network Time Protocol) is widely used for computer clock synchronization in  internet. There are various versions of NTP. Latest version as of Jun 2010 is NTPv4 and is well described in RFC5905. NTP4 is modified to accommodate IPv6 and other improvement has been done over NTPv4. 

Are you getting 'Peer Unreachable' when you try to syc with NTP server?
Usually there are various reasons behind the problem.

1. Firewall or port filter : Make sure that default UDP port 123 is open. You can test this real quick just by turning off Firewall.

2. Windows Time Service (w32time) not running on the appropriate mode
There are various modes of operation for Windows Time Service as NTP supports several different packet types.

Normally NTP client sends 'client' mode request packets to a NTP server

NTP server responds back with 'server' mode packet with timing information

By default some windows (esp. XP and earlier) sends 'symmetric active' mode packet instead of 'client' mode request packets. 'symmetric active' mode packets is for NTP's peering feature where a pool of computers(peers) are configured to sync their clocks among each others to agree upon a common 'network time', which then can be supplied to the client.

Usually NTP server drops 'symmetric active' mode packets, unless it is told to do so.

Q: How can I switch to 'client' mode of Windows Time Service?

Ans: You have to change the Windows registry and it can be done easily via command line

w32tm /config /manualpeerlist:ntp.myserver.com,0x8 /syncfromflags:MANUAL

Here, ntp.myserver.com is my NTP server

http://support.microsoft.com/kb/875424

The valid settings for the mode used with the /manualpeerlist switch include the following:

0x01 - use special poll interval SpecialInterval
0x02 - UseAsFallbackOnly
0x04 - send request as SymmetricActive mode
0x08 - send request as Client mode

The mode that Windows Time uses to send requests is set by the following registry subkey:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time\TimeProviders\NtpServer

0x8 enables 'client' mode for Windows Time Service
syncfromflags:MANUAL forces Windows Time Service to use manualpeerlist for the time query.

Make changes effective immediately
w32tm /config /update

To resync manually
w32tm /resync

Additional Tips:
If you want to sync with time server everyday, you can create a new 'Scheduled Task' under Control Panel --> Scheduled Task to run 'w32tm /resync' everyday at your specified time.

Good Luck!

Integrate Asterisk with SIP enabled Wireless phone: Polycom SpectraLink 8030

2012-01-20T07:05:00.001-08:00

If you are looking for SIP and 802.11a/b/g compatible wireless phone, SpectraLink 8030 can be one of your choices. It is compatible with Asterisk. It has also Push-To-Talk (PTT) functionality that allows group communication just like Walky Talky.

Product information of SpectraLink 8030 can be found at
http://www.polycom.com/products/voice/wireless_solutions/wifi_communications/handsets/spectralink_8030_wireless.html

Software and documents for SpectraLink 8030 can be downloaded from following link from Polycom
http://support.polycom.com/PolycomService/support/us/support/voice/wi-fi/spectralink_8030_wireless.html

If you are using Polycom SpectraLink VIEW certified Wireless Access Point, you can call 1-800-Polycom and get the support. If not, there is no luck to get any kind of support from them.

In my case, we have

DHCP , DNS, NTP and TFTP server running on Linux
Xirrus Array - XN4, XN8 (Make sure your wireless AP supports WMM- Wi-Fi Multimedia; sometime you might have to upgrade to the latest firmware. Contact your Wireless AP vendor if your AP doesn't have WMM enabled)
Asterisk Server (SIP server + PBX) : IP address 192.168.1.10
SpectraLink 8030 ( one has an extension 2000 and other has an extension 3000)
Voicemail (Extension 2100)

In this article, I am not going to show you how to configure DHCP, DNS, NTP, TFTP server. If you need any help, contact your Server Administrator or look for online help.

Step1: Publish the required firmwares and configs to TFTP server
Download SIP software of SpectraLink 8030 from above link
Unzip it and publish the content to TFTP server

You will see various .bin files and .cfg files.

In my case, I have following files
#tftpshare
MIBs
pd14csi.bin
pd14odsi.bin
pd14shim.bin
pd14shsi.bin
pd14udsi.bin
pi1400si.bin
settings.txt
slnk_cfg.cfg

sip_allusers.cfg
sip_2000.cfg

sip_3000.cfg

You don't have to touch .bin files. You don't even have to touch slnk_cfg.cfg file

All you need to do is edit sip_allusers.cfg and create the config files for individual extensions (in my case I have two SpectraLink. I want to extensions: 2000 and 3000)

#vi sip_allusers.cfg
#--------Configuration for Asterisk based system-------------
PROXY1_TYPE            = Asterisk
PROXY1_ADDR            = 192.168.1.10:5060 #IP address of Asterisk Server
PROXY1_KEYPRESS_2833   = enable
PROXY1_KEYPRESS_INFO   = disable
PROXY1_HOLD_IP0        = disable
PROXY1_PRACK           = enable
PROXY1_REREG_SECS      = 3600
PROXY1_KEEPALIVE_SECS = 14
PROXY1_CALLID_PER_LINE = disable
PROXY1_MAIL_ACCESS     = 2100

Create a config file for an extension 2000
#vi sip_2000.cfg
LINE1         = 2000
LINE1_PROXY   = 1
LINE1_CALLID = Spectralink x2000
LINE1_AUTH    = 2000; myp@ssw0rd

#Note- Password follows extension in LINE1_AUTH line

Similarly create a config file for an extension 3000

#vi sip_3000.cfg
LINE1         = 3000
LINE1_PROXY   = 1
LINE1_CALLID = Spectralink x3000
LINE1_AUTH    = 3000; myp@ssw0rd
#Note- Password follows extension in LINE1_AUTH line

Step2: Configure Asterisk Server

Spectralink 8030 wouldn't register to Asterisk server. I have to go thru' rigorous troubleshooting before I could figure out the fact that SpectraLink 8030's latest SIP software is still based on the original SIP RFC 2543. [ Polycom support didn't want to talk about anything as I wasn't using their VIEW certified AP. ]

[Please read about fundamental SIP request header if you haven't done so far]

However Asterisk is designed on the basis of latest SIP RFC 3261. Asterisk server drops the REGISTER request coming from SpectraLink 8030 because as per RFC 2543 standard SpectraLink doesn't send tag id in SIP REQUEST FROM header.

Thus you have to tell Asterisk to ignore the tags in SIP request headers. You can do that by using global option in sip.conf

Asterisk 1.8 has pedantic=yes by default

;pedantic=yes ; Enable checking of tags in headers,
                                ; international character conversions in URIs
                                ; and multiline formatted headers for strict
                                ; SIP compatibility (defaults to "yes")

You have to use pedantic=no for SpectraLink 8030 to work with Asterisk

#vi sip.conf

[general]

bindport=5060
bindaddr=192.168.1.10
canreinvite=no
dtmfmode=auto
pedantic=no

[2000]
type=friend
host=dynamic
context=YourContextinDialplan

username=2000
callerid="Dave One" <2000>
secret=myp@ssw0rd
mailbox=2000

[3000]
type=friend
host=dynamic
context=YourContextinDialplan

username=3000
callerid="John One" <3000>
secret=myp@ssw0rd
mailbox=3000

Step3: Configure AP
Different APs have different tools for wireless configuration. Make sure you are using 802.11a/b/g wireless APs. AP must be configured as WMM-PowerSave. Please go thru' the product guide that came along with your AP to enable WMM-PowerSave.

Create a SSID for your voice network. [You many not want to broadcast this SSID to minimize easy access to SSID by intruders]

You can use any kind of encryption you want to. I prefer WPA2 as it uses Pre-Shared Key(PSK) and it allows user to manually enter keys to initiate WPA security.

Example:
SSID: spectralinknetwork
WPA2 passphrase: myp@ssword

Make sure various Radio bands are available for use. I have enabled a/g band and I am going to use '802.11a standard' for my SpectraLink phones.

BONUS INFORMATION: Brief introduction on various wireless standards:

802.11a standard operates in 5GHz band with maximum data rate of 54Mbps. It's range is lower than the range of 802.11b but offers higher number of channels and also higher data rate.
802.11b standard operates in 2.4GHz band with maximum data rate of 11Mbps. It's range is higher range than 802.11a but it suffers interference from other devices like Bluetooth, cordless telephonesc etc operating at 2.4 GHz. Data rate offered is less than 802.11a.
802.11g standard operates in 2.4GHz just like 802.11b, but operates at maximum data rate of 54Mbps.
802.11n standard operates in 5GHz and/or 2.4GHz using MIMO technology.

Step4: Use SIP HAT(Handset Administration Tool) provided by Polycom to configure the initial configuration for SpectraLink 8030. You can download SIP HAT from above provided link

Network Configuration of SpectraLink via SIP HAT Tool

Enable DHCP
Use SSID:spectralinknetwork and WPA2 passphrase: myp@ssword and click on 'Generate PSK from Passphrase + SSID' button
Use QoS Type 'Wi-Fi Standard'
Admission Control: Optional
802.11 Config: a
Enable the bands you want to use

SIP configuration and others via SIP HAT Tool

Change the TimeZone as required
Enter the SIP username: 3000 and password: myp@ssword

Follow the procedure as per instructed by SIP HAT Software to write the settings to SpectraLink 8030 handset. It might prompt for the password before you can write the settings to the handset. Default password is '123456'. Ignore any minor errors while writing the settings to handset as handset will download the latest firmware from your TFTP server anyway.

Step5: Powercycle the handset. If your ducks are in row, it will work without hassle. If come across any issues, follow the SpectraLink 8020/8030 Wireless Telephone Administration Guide for SIP.

SpectraLink 8030 displays Startup Sequence: 1 thru' 9. Let's say your handset is stuck at '1234567', it means it has successfully gone thru '8' and '9', but it is stuck at '7'. If you look on the administrative guide, '1234567' means DHCP response with bad DNS server configuration. So, you have to fix possible DNS/DHCP server issue.

If you need further help, you can email me at erdevendra@gmail.com or simply post the comment.

NS2 simulation for PIM-SM multicasting

2011-12-20T20:21:00.000-08:00

I am going to show you how to perform traditional PIM-SM simulation in NS2. For those who doesn't know PIM-SM (Protocol Independent Multicast - Sparse Mode) check the RFC 4601 .

Definitions extracted from RFCs:
PIM-DM (RFC3973) is a multicast routing protocol that uses the underlying unicast routing information base to flood multicast datagrams to all multicast routers. Prune messages are used to prevent future messages from propagating to routers without group membership information.

PIM-SM (RFC4601) is a multicast routing protocol that can use the underlying unicast routing information base or a separate multicast-capable routing information base. It builds unidirectional shared trees rooted at a Rendezvous Point (RP) per group, and optionally creates shortest-path trees per source.

In simple language, PIM-DM uses a push model to flood multicast traffic to every corner of the network. This process is considered to be very “heavy”, since it floods its message to all sub-networks. In PIM-SM environments only sub-networks that have active receivers that have explicitly requested the data will be forwarded the multicast traffic. PIM-SM introduces the concept of Rendezvous Point (RP). The RP it is a appointed router where all the multicast messages flow and from witch it forward through the multipoint tree.

The Network Simulator2 (NS-2) is the most popular simulator in the scientific field and in the great telecommunications companies, allowing the creation of any network topology and analyze any kind of protocol.

SIMULATION SCENARIO:

This simulation simulates PIM-SM environment based IP infrastructure with one multicast source, one group address and two nodes joining the group. Node0 thru Node7 are all routers. Source1 is attached to Router0. Receiver1 and Receiver2 are attached to Router6 and Router7 respectively. Router1 is defined as Rendezvous Point (RP).

Source1 starts at 0.5 sec

Receiver1 joins the group at 1.0 sec

Receiver2 joins the group at 1.5 sec

Receiver1 leaves the group at 6.0 sec

Receiver2 leaves the group at 6.5 sec

Source1 stops at 9.5 sec

Network Topology for multicast simulation

File: mulicast.tcl

#//////////////////CODE STARTS HERE/////////////////////////////////

#Create an event scheduler wit multicast turned on

set ns [new Simulator -multicast on]

#$ns multicast

#Turn on Tracing

set tf [open output.tr w]

$ns trace-all $tf

# Turn on nam Tracing

set fd [open mcast.nam w]

$ns namtrace-all $fd

# Create nodes

set n0 [$ns node]

set n1 [$ns node]

set n2 [$ns node]

set n3 [$ns node]

set n4 [$ns node]

set n5 [$ns node]

set n6 [$ns node]

set n7 [$ns node]

# Create links

$ns duplex-link $n0 $n1 1.5Mb 10ms DropTail

$ns duplex-link $n1 $n2 1.5Mb 10ms DropTail

$ns duplex-link $n2 $n3 1.5Mb 10ms DropTail

$ns duplex-link $n3 $n4 1.5Mb 10ms DropTail

$ns duplex-link $n1 $n4 1.5Mb 10ms DropTail

$ns duplex-link $n3 $n5 1.5Mb 10ms DropTail

$ns duplex-link $n5 $n6 1.5Mb 10ms DropTail

$ns duplex-link $n5 $n7 1.5Mb 10ms DropTail

# Allocate group addresses

set group1 [Node allocaddr]

set group2 [Node allocaddr]

# Routing protocol: PIM-SM

$ns mrtproto BST

BST set RP_($group1) $n1

# UDP Transport agent for the traffic source

set udp0 [new Agent/UDP]

$ns attach-agent $n0 $udp0

$udp0 set dst_addr_ $group1

$udp0 set dst_port_ 0

set cbr1 [new Application/Traffic/CBR]

$cbr1 set packetSize_ 210

$cbr1 set rate_ 1000k

$cbr1 attach-agent $udp0

# Create receiver

set rcvr1 [new Agent/Null]

$ns attach-agent $n6 $rcvr1

set rcvr2 [new Agent/Null]

$ns attach-agent $n7 $rcvr2

$ns at 1.0 "$n6 join-group $rcvr1 $group1"

$ns at 1.5 "$n7 join-group $rcvr2 $group1"

$ns at 6.0 "$n6 leave-group $rcvr1 $group1"

$ns at 6.5 "$n7 leave-group $rcvr2 $group1"

# Schedule events

$ns at 0.5 "$cbr1 start"

$ns at 9.5 "$cbr1 stop"

#post-processing

$ns at 10.0 "finish"

proc finish {} {

global ns tf

$ns flush-trace

close $tf

exec nam mcast.nam &

exit 0

}

# For nam

#Colors for packets from mcast packets

$ns color 10 red

#udp0 traffic has flow ID 10

# Group 0 source

$udp0 set fid_ 10

$n0 color red

$n0 label "Source 1"

$n6 label "Receiver 1"

$n6 color blue

$n7 label "Receiver 2"

$n7 color blue

# Animation rate

$ns set-animation-rate 3.0ms

$ns run

#//////////////////CODE ENDS HERE/////////////////////////////////

Make sure that you make your .tcl file executable

#chmod 700 multicast.tcl

Execute the .tcl file as

#ns multicast.tcl

If you run into any issues, refer to NS2 documentation. It's really nice documentation.

Apache2.2: Defining Virtual Hosts, Re-direction and LDAP authentication uncovered

2011-12-01T12:56:00.000-08:00

I usually put references at the bottom of the article. But this time I want to put it in the beginning of the article. If you are Apache beginner, trust me you want to go through these references before you start doing anything.

References:
Apache Directives: http://httpd.apache.org/docs/2.2/mod/directive-dict.html#Context
Name-Based Virtual Hosts: http://httpd.apache.org/docs/2.2/vhosts/name-based.html
LDAP directory for authentication: http://httpd.apache.org/docs/2.3/mod/mod_authnz_ldap.html
LDAP and Active Directory Terminologies: http://rapidtechguide.blogspot.com/2011/07/directories-terminology-active.html

Practice Scenario:

Windows Server
Web Server: Apache2.2
IP add: 192.168.1.10
Port: 80
Websites hosted:
www1.test.org
www.mytest.org
www.urtest.org
www.ourtest.org
www.everyonetest.org
www.lovetest.org

Before you start testing your apache setup make sure that DNS is configured properly, hosts file is configured properly.

STEP1:
File: C:\Windows\System32\drivers\etc\hosts
192.168.1.10 www1.test.org
192.168.1.10 www.mytest.org
192.168.1.10 www.urtest.org
192.168.1.10 www.ourtest.org
192.168.1.10 www.everyonetest.org
192.168.1.10 www.lovetest.org

#everyonetest.org and lovetest.org are alias of ourtest.org

STEP2:
Configure DNS server to point those domains 'mytest.org, urtest.org, ourtest.org,everyonetest.org,lovetest.org' to 192.168.1.10. You can contact your DNS administrator

STEP3:
Say Apache2.2 is installed in C: drive
C:\apache

and you are publishing your web contents at C:\website
C:\website\mytest
C:\website\urtest
C:\website\ourtest

STEP4:
C:\apache\conf\httpd.conf

# Change this to Listen on specific IP addresses as shown below to
# prevent Apache from glomming onto all bound IP addresses.
Listen 192.168.1.10:80

#uncomment these for LDAP authentication support
LoadModule authnz_ldap_module modules/mod_authnz_ldap.so
LoadModule ldap_module modules/mod_ldap.so

ServerName www1.test.org

#
# DirectoryIndex: sets the file that Apache will serve if a directory
# is requested.
#
<IfModule dir_module>
DirectoryIndex index.htm index.html index.shtml index.html.var index.php index.pl default.html default.htm
</IfModule>

#Set LogLevel to debug if you are configuring Apache for first time so that you can collect enough logging information for troubleshooting purpose
LogLevel debug

<IfModule mime_module>
#Uncomment this line to have shtml MIME support
AddType text/html .shtml
</IfModule>

# Uncomment following line to add Virtual hosts in different file
Include conf/extra/httpd-vhosts.conf

STEP5:
C:\conf\extra\httpd-vhosts.conf
#
# Use name-based virtual hosting.
#
NameVirtualHost 192.168.1.10:80

#Regular Virtual Host Configuration Example
# WWW.MYTEST.ORG BEGIN
# mytest.org is published at C:/website/mytest

<VirtualHost 192.168.1.10:80>
ServerName www.mytest.org
DocumentRoot C:/website/mytest

<Directory C:/website/mytest>
AllowOverride None
Order deny,allow
Allow from all
</Directory>

ErrorLog "logs/www.mytest.org-error.log"
CustomLog "logs/www.mytest.org-access.log" common

ErrorDocument 401 /unauth.shtml
ErrorDocument 403 /forbid.shtml
ErrorDocument 404 /notfound.shtml
ErrorDocument 500 /error.shtml
</VirtualHost>

# WWW.MYTEST.ORG END

#Re-Direction Configuration Example
# WWW.URTEST.ORG BEGIN
# urtest.org is simply re-directed to www.wikipedia.org

<VirtualHost 192.168.1.10:80>
ServerName www.urtest.org
Redirect permanent / https://www.wikipedia.org
</VirtualHost>

# WWW.URTEST.ORG END

#LDAP Authentication Configuration Example
# WWW.OURTEST.ORG BEGIN
# ourtest.org is published at C:/website/ourtest
# LDAP authentication is required to access the conents of C:/website/ourtest

<VirtualHost 192.168.1.10:80>
ServerName www.ourtest.org
ServerAlias everyonetest.org lovetest.org
DocumentRoot C:/website/mytest

<Directory C:/website/mytest>
AllowOverride None
Order deny,allow
Allow from all

AuthType Basic
AuthBasicProvider ldap
AuthzLDAPAuthoritative on

AuthLDAPBindDN "cn=ldapuser,ou=\"Super Accounts\",DC=ad,DC=test,DC=org"
AuthLDAPBindPassword ipassword

AuthName "Only for registered users"

AuthLDAPURL "ldap://ldap.test.org:389/ou=students,ou=toefl,dc=ad,dc=test,dc=org?name"
require valid-user
</Directory>

ErrorLog "logs/www.mytest.org-error.log"
CustomLog "logs/www.mytest.org-access.log" common

ErrorDocument 401 /unauth.shtml
ErrorDocument 403 /forbid.shtml
ErrorDocument 404 /notfound.shtml
ErrorDocument 500 /error.shtml
</VirtualHost>

# WWW.OURTEST.ORG END

Some other tips:
I would prefer to use Internet Explorer(IE) for testing webpages as lots of users are using IE. In IE go to Tools--> Internet Options and Check 'Delete Browsing History on Exit". Sometimes Internet Browser displays webpages from it's temp files, so even if your apache/web server is stopped you might see webpages working (I have seen it and it took me quite a time to get around with it). Or sometimes if you make some content changes, your browser may not reflect those changes. So, while perfoming apache setup and testing 'Delete Browsing History' really helps. Close the browser. Re-open the browser and see if you got ur desired output.
Sometime you might have to flush local DNS cache. If you have to you can use following command
> ipconfig /flushdns

Good Luck!!!

Additional References:
http://www.yolinux.com/TUTORIALS/LinuxTutorialApacheAddingLoginSiteProtection.html

Write Startup scripts in Linux Environment?

2011-11-22T12:42:00.000-08:00

Explanation is based on SLES (SUSE Enterprise Linux). It could be related to other distributions of Linux as well.
There are various situations where you write your own script and want it to run at system startup. In Linux environment you have to place your script in /etc/init.d and use 'insserv' command or 'chkconfig' config to insert those script in various runlevels.

[By default, insserv insert the script in runlevel 3 and 5. You can check that by running #chkconfig --list ]

Let's say I want to run 'asterisk' program automatically at startup and I want to make sure that it starts only when all the services of OS are up.

'which' command returns me the location of the program or application#which asterisk

/usr/bin/asterisk

Create a script file in /etc/init.d directory

#vi /etc/init.d/asteriskStartupScript
#!/bin/bash
#Copyright (c) 2011 DShah
# All rights reserved
#
#Author: DShah, 2011
# /etc/init.d/asterisk
#PLEASE READ /etc/init.d/skeleton to understand various parameters in startup scripts
#
### BEGIN INIT INFO
# Provides: asterisk
# Required-Start: $ALL
# Required-Stop:
# Default-Start: 3 5
# Default-Stop: 0 1 2 6
# Short-Description: Starts Asterisk
### END INIT INFO

#Start service
/usr/sbin/asterisk

Save and close the script file.

'chmod' command can be use to add executable permission

#chmod 744 /etc/init.d/aseriskStartupScript

'insserv' command can be used to insert the script in desired runlevel as specified in script file

#insserv asteriskStartupScript

'chkconfig' command can be used to check if the script will run in next startup

#chkconfig --list asteriskStartupScript

Reference:
http://www.novell.com/coolsolutions/feature/15380.html

PERL scripting: Export data from MySQL database in XML format

2011-10-14T06:21:00.000-07:00

I have a MySQL database containing all the data but the application I am trying to use only supports XML. How can I export data from MySQL database in XML format?

Here is your answer. You need to select a programming language that support MySQL connection and does pretty good string manipulation. I found PERL programming very easy and powerful doing both MySQL connection and String Manipulation.

Assumptions: I will be running my PERL script on the same server with MySQL database. MySQL Username and Password are 'username' and 'password' respectively. Database name is 'phonesDB' and table name is 'phones'.

MySQL
Database:	phonesDB
Table:	phones

full_name	phone_number	department
Peter Griffin	25962	Technology
Stewie Griffin	25963	Finance
Sam Burns	25234	HR

You should have some basic concept of XML, MySQL and PERL programming knowledge.

[Note: Make sure that you have perl-DBD-mysql, perl-DBI and perl installed. If those package are missing, you can use YaST, YUM, ZYPPER, APT-GET to install those missing packages based on your distro.]

Let's write the PERL script that will access our MySQL database and generate XML file for us.

#vi myPerlscript.pl
#!/usr/bin/perl
use strict;
use DBI;
use DBD::mysql;

#connect to the database phonesDB using login credentials
my $dbh = DBI->connect("DBI:mysql:phonesDB","username","password",{RaiseError => 1, PrintError => 0});

#run the SELECT query
my $sth = $dbh->prepare("SELECT full_name,phone_number,department FROM phones");
$sth->execute();

print "<?xml version=\"1.0\" encoding=\"utf-8\"?>\n";
print "<directory>\n";
print " <local>true</local>\n";
print " <sorted>true</sorted>\n";
print " <name>Company_Name</name>\n";
while (my ($full_name,$phone_number,$department) = $sth->fetchrow_array ())
{

print " <user>\n";

#Using string manipulation techniques available in PERL scripting
#Extract first and last name from full name
#index() function returns the occurrence of $myspace in $full_name
#substr() function allows to copy part of a string from another by specifying beginning position and the length of string my $myspace =" ";
my $myindex =index($full_name,$myspace);
my $last_name=substr($full_name,$myindex+1);
my $first_name=substr($full_name,0,$myindex);

print " <name>$last_name, $first_name</name>\n";
print " <company>$site_name</company>\n";
print " <contact>\n";
print " <type>phone</type>\n";
print " <uri>sip:$phone_number</uri>\n";
print " </contact>\n";
print " </user>\n";
}

#Disconnect the database connection
$dbh->disconnect ();
print "</directory>\n";

Let's make the script executable
#chmod u+w myPerlscript.pl

Now run the script, you will get output in XML format
#./myPerlscript.pl

If you want to save the output of the script to the file,
#./myPerlscript.pl > myXMLfile.xml

Output:

References:
MySQL connection using PERL
String Manipulation using PERL

Configured server with multiple NICs on different subnet. Can't PING IP add on second NIC? Here's the solution

2011-10-10T18:52:00.000-07:00

Let's say we have a network problem as shown below (User can't access 10.1.1.10 from the workstation. User fails to ping 10.1.1.10 from workstation):

Note: In Linux, usually NIC1 is presented as eth0 and NIC2 is presented as eth1

How to fix the problem associated with accessing 10.1.1.10 from workstation?

You must configure multiple default routes in the server.
You can possibly achieve this in different ways, however I prefer the use of IP ROUTE and IP RULES. It's easy to implement and understand.

Step 1: Create a new policy routing table
# echo "1 TenNetwork" >> /etc/iproute2/rt_tables

Routing tables are declared in rt_tables. Here we declared TenNetwork table as we are going to write a set of rules associated with 10 network. You can give it any name you want.

Step2: Define routes in the table
#ip route add 10.1.0.0/16 dev eth1 src 10.1.1.10 table TenNetwork

#ip route add default via 10.1.1.1 dev eth1 table TenNetwork

Here we simply declared that NIC2(eth1) is associated with 10.1.0.0 subnet and it's IP address is 10.1.1.10. We also defined the default route via 10.1.1.1 on eth1 interface. (This is second default route. The first one is defined in 'main' routing table and the default route is via 192.168.2.1 on eth0 interface. OS automatically picks the first default route from eth0. You can check that by executing #ip rule show or #netstat -anr command)

#ip rule show

Since we haven't defined any rule associated with TenNetwork table yet, we can't see TenNetwork table in the rules.

Step3: Define the rules associated with TenNetwork table

#ip rule add from 10.1.1.10/32 table TenNetwork
#ip rule add to 10.1.1.10/32 table TenNetwork

Here we are defining a rule that says, if any packet is FROM/TO to 10.1.1.10, lookup the TenNetwork table.

#ip rule show
#netstat -anr

Now you can see the active routing rules associated with TenNetwork table as well.

You should be able to ping 10.1.1.10 from workstation now. (However I can't guarantee). If you are lucky, it will work like charm. If you are more lucky, you will discover more on routing and fix the problem by yourself. Good Luck!!!

Run WireShark on the server before and after applying the rule. You can visualize the problem and see how the problem is resolved. I love WireShark. I think people can find and fix more then 90% network problems using WireShark.

Warning!!!! :
1. Restarting the server will loose the configuration
2. Restarting the network will loose the configuration

Let's solve the problem associated with restarting the server. We will write startup script.

#vi /etc/init.d/TenNetwork
#!/bin/bash
#Copyright (c) 2011 DShah
# All rights reserved
#
#Author: DShah, 2011
# /etc/init.d/TenNetwork
#PLEASE READ /etc/init.d/skeleton to understand various parameters in startup scripts
#
### BEGIN INIT INFO
# Provides: TenNetwork
# Required-Start: $network
# Required-Stop:
# Default-Start: 3 5
# Default-Stop: 0 1 2 6
# Short-Description: Fixes 10 Network routing issue
### END INIT INFO

$logFile=/var/log/ten-network-log
ip route add 10.1.0.0/16 dev eth1 src 10.1.1.10 table TenNetwork
ip route add default via 10.1.1.1 dev eth1 table TenNetwork
ip route show 2>&1 >> $logFile
ip rule add from 10.1.1.10/32 table TenNetwork
ip rule add to 10.1.1.10/32 table TenNetwork
ip rule show 2>&1 >> $logFile
ip route show 2>&1 >> $logFile

Save and close the file

#chmod 700 /etc/init.d/TenNetwork

'insserv' command can be used to insert the script in desired runlevel as specified in script file
# insserv TenNetwork

You can go to /etc/init.d/rc3.d and /etc/init.d/rc5.d and look the startup order of TenNetwork.

Restart your server and see if it is working as you expected.

Reference:
http://www.policyrouting.org/PolicyRoutingBook/ONLINE/TOC.html

How to install flash player for firefox/mozilla in Linux (CentOS, RedHat, SuSE, SLES etc)

2011-09-27T13:53:00.000-07:00

Just installed linux and can't play YOUTUBE or other flash based programs...... No more scratching heads.
Go to adobe website to download the flashplayer: http://get.adobe.com/flashplayer/

Download the appropriate file based on your OS. (32-bit or 64-bit linux).

I would recommend you to download .tar.gz file of the flashplayer.

Once the file is downloaded, you simply need to extract it. Extract is within the folder.

#mkdir myFlashdir
#cd myFlashdir

copy flashplayer.tar.gz in this folder

#tar xvzf flashplayer.tar.gz

Now you will see libflashplyer.so plugin-file for mozilla. You simply need to copy this file to

/usr/lib64/mozilla/plugins ==> If your linux is 64-bit

/usr/lib/mozilla/plugins ==> If your linux is 32-bit

#cp libflasplayer.so /usr/lib64/mozilla/plugins

You are done. Now have fun with you Youtube or other flash programs.

You can check the plugins installed by typing following in the URL field.

about:plugins

Dell Latitude + Linux : Easy to solve the problem with Wireless setup

2011-07-27T09:49:00.001-07:00

Step 1: Download the linux based driver for your NIC card in your Dell Latitude laptop. My laptop has Broadcom Wireless controller. You can check yours by running the command

#lspci |grep -i 802.11

Mine is: Network controller: Broadcom Corporation BCM4321 802.11a/b/g/n (rev 03)
Luckily I found the driver at Broadcom website.

Check if your system has 32-bit Linux or 64-bit Linux and download the appropriate driver. You can check that via

#uname -a

Mine is 64-bit SUSE Linux: Linux devsuse 2.6.32.12-0.7-default #1 SMP 2010-05-20 11:14:20 +0200 x86_64 x86_64 x86_64 GNU/Linux

Step2: Follow README.txt for that driver. It has clear instruction.

[extract from README.txt]


# lsmod  | grep "b43\|ssb\|wl"

If any of these are installed, remove them:
# rmmod b43
# rmmod ssb
# rmmod wl

To blacklist these drivers and prevent them from
loading in the future:
# echo "blacklist ssb" >> /etc/modprobe.d/blacklist.conf
# echo "blacklist b43" >> /etc/modprobe.d/blacklist.conf

>>1. Unzip, build and install the driver
Setup the directory by untarring the proper tarball:

For 32 bit:  hybrid-portsrc_x86-32_v5.100.82.38.tar.gz
For 64 bit:  hybrid-portsrc_x86-64_v5.100.82.38.tar.gz

Example:
# mkdir hybrid_wl
# cd hybrid_wl
# tar xzf /hybrid-portsrc_x86-32_v5.100.82.38.tar.gz

Build the driver as a Linux loadable kernel module (LKM):

# make clean   (optional)
# make

When the build completes, it will produce a wl.ko file in the top level
directory.


>>2: Insmod the driver.

Otherwise, if you have not previously installed a wl driver, you'll need
to add a security module before using the wl module.  Most newer systems
use lib80211 while others use ieee80211_crypt_tkip. See which one works for
your system.

# modprobe lib80211 
  or 
# modprobe ieee80211_crypt_tkip

Then:
# insmod wl.ko

wl.ko is now operational.  It may take several seconds for the Network
Manager to notice a new network driver has been installed and show the
surrounding wireless networks.

Step3. Check if you can see the wireless card detected.
#ifconfig
#iwconfig

or Go to yast2 --> Network Devices --> Network Settings --> Overview
You should see your wireless network card listed.

Step4: Configure your wireless as you do with your regular wireless setup. Good Luck!!!
(You can refer to Novell Documentation if you need any help to configure your Wireless network)

If your internet/network connectivity doesn't wok, check if the routing table is good.

#route -n

You can define the default route for 0.0.0.0 (any) through your wireless interface ( in my case it's eth1). For that you can go to YAST2-->Network Devices-->Network Settings-->Routing

Also make sure that you have DNS servers defined. If not, you can go to YAST2 -->Network Devices-->Network Settings-->Hostname/DNS
or you can also edit /etc/resolv.conf

NOTE: Upgrading the kernel and drivers requires removing ssb, b43 and adding them to the blacklist again.

Directories Terminology: Active Directory, eDirectory, Lotus Domino Directory

2011-07-06T08:25:00.000-07:00

LDAP is very often used to access the directories. Directory could be Active Directory, eDirectory/Novell NDS, Lotus Domino Directory and more.
There are too many acronyms like DN, DC, OU, CN, GPO and they are easy to understand

AD: Active Directory
DN : Distinguished Name
DC: Domain Controller/Component
OU: Organizational Unit
CN: Common Name
GPO: Group Policy

Fig. Organization tree structure depicted by AD heirarchy

In Active Directory , eDirectory or any LDAP compliant directory , objects are referred to by Distinguished Name (DN) . The parts of a distinguished name, delimited by commas, represent where in AD hierarchy the object exists.

Monikers in a DN are:

CN Common Name cn=Joe Dirt
OU Organization Unit ou=Staff
DC Domain Controller/Component dc=UPS

An example of the Distinguished Name of a user object could be:

cn=Joe Dirt, ou=Staff, ou=Finance, ou=Dept, ou=UPS, dc=ad, dc=ups, dc=com

In this case, the object with Common Name 'Joe Dirt' is in the Organizational Unit 'Staff', which in turn is in the Organizational Unit 'Finance', which in turn is in the Organizational Unit 'Dept', which in turn is in Organization Unit 'UPS', which is in the domain 'ad.ups.com'.

You can use various free LDAP browsers like Softerra , JXplorer to browse directories.

More examples to clarify the concept:
If you want to refer to all the objects under UPS Organizational Unit/Container, you should use

BASE DN: ou=UPS, dc=ad, dc=ups, dc=com

If you want to refer to all the objects under Finance Organizational Unit/Container, you should use

BASE DN: ou=Finance, ou=Dept, ou=UPS, dc=ad, dc=ups, dc=com

If you want to login as Joe Dirt to make LDAP query, you should use following DN

USER DN: cn=Joe Dirt, ou=Staff, ou=Finance, ou=Dept, ou=UPS, dc=ad, dc=ups, dc=com

CN is used for the default system based containers. OU is also used for containers. One major difference between a CN container and a OU container is that GPOs can be applied only to OUs, not to CNs.

Reference: wiki, forums and various text books

DHCP IPv4 vs IPv6 : Basic concept

2011-06-05T15:55:00.000-07:00

Most of us are familiar with DHCP (Dynamic Host Configuration Protocol). We use it all the time to get an IP address and network configurations for our devices like laptop, computers, handheld IP devices, IP TV and more... It makes our life easy as we don't have to manually define the IP address for our system and we also don't have to worry about IP address duplication problem. DHCP takes care all of those for us.

We all know that IPv6 is drilling our internet world and it's going to replace IPv4. There is going to be revolution. DHCP is one of those areas. Architecture of DHCPv4 (IPv4 system) and DHCPv6 (IPv6) are totally different. I will try my best to explain the differences in very easy language.

1. In IPv4 systems, hosts send broadcast traffic requesting an IP address in hope to get reply from the DHCP server, thus network doesn't know how far to send the request.

But all IPv6 systems support multicasting and DHCPv6 servers are ready to receive DHCPv6 multicast packets. Thus network knows where to send the DHCP requests from clients. (FF02::1:2 is a link-scoped multicast address used by a client to communicate with neighboring i.e on-link, relay agents and server. All servers and relay agents are members of this multicast group)

[Wireshark capture for DHCPv6: notice a link-scoped multicast address. I intentionally hid my link-local address(IPv6) of my laptop which acts as IPv6 host ]

2. In IPv4 systems, clients doesn't have any valid IP address to start with. It uses 0.0.0.0 as it's initial IP address and sends request (requesting IP address and network configuration ) broadcast traffic to 255.255.255.255 in hope to get response from DHCP servers.

(Here is the complete DHCPv4 request-reply messaging in IPv4 environment: captured by wireshark using filter BOOTP. DHCPv4 uses BOOTP)

In IPv6 systems, each hosts have valid link-local address that can be used to send traffic on the link it is connected to, thus makes it possible to send request to DHCP server for REAL address.

There are more to talk... But I have to watch NBA finals: MAVS vs Heat. :D
I will keep on updating this article.

Reference:
http://www.ietf.org/rfc/rfc3315.txt
http://www.isc.org/community/blog/201104/isc-dhcp-and-ipv6-dhcpv6-story
http://en.wikipedia.org/wiki/IPv6#Stateless_address_autoconfiguration

Centralized LogServer in SuSE Linux

2011-05-25T06:51:00.000-07:00

LogServer: ServerA [IP address: 192.168.1.5]
NetworkServers: ServerB, ServerC... and more

ServerB-------send log files-----> ServerA[LogServer] <-----------send log files---- ServerC

Here we want ServerB, Server C to send it's log file to ServerA for centralized access of log files.

Daemon: syslog-ng
Files:
/etc/sysconfig/syslog
/etc/syslog-ng/syslog-ng.conf

Commands:
/etc/init.d/syslog start|restart|stop

ps aux|grep syslog --> to see if syslog-ng is running or not

SuSEconfig --module syslog-ng --> to reload the change done on /etc/syslog-ng/syslog-ng.conf

Configure LogServer i.e ServerA to accept the log files from NetworkServers

Edit /etc/syslog-ng/syslog-ng.conf on ServerA(Log Server)

source src {
#
# include internal syslog-ng messages
# note: the internal() soure is required!
#
internal();

#
# the default log socket for local logging:
#
unix-dgram("/dev/log");

#
# uncomment to process log messages from network:
#
udp(ip("0.0.0.0") port(514));
#I uncommented above line telling ServerA to accept the log files from network
};

At the bottom of this file, I defined the destination and log

#
#Added by DShah 05/25/11
#
destination std { file("/var/log/HOSTS/$YEAR-$MONTH/$HOST/$FACILITY-$YEAR-$MONTH-$DAY" owner(root) group(root) perm(0600) dir_perm(0700) create_dirs(yes));
};

log { source(src);
destination(std);
};

Over here I am telling ServerA to process the log files coming source src to destination std.
Destination std tells ServerA to save log messages from each host in a separate directory called /var/log/HOSTS/YEAR-MONTH/hostname/.

Now run the command
#SuSEconfig --module syslog-ng --> to reload the config changes done

#/etc/init.d/syslog restart OR
#syslog-ng restart

#ps aux|grep syslog --> to check if syslog-ng is running

If you need to kill syslog-ng process for any reason, you can simply run the command

#killall syslog-ng
or
#kill -9 [PID-of-syslog-ng]

Configure NetworkServers (Server B, ServerC... ) to send log files to LogServer(ServerA):

Edit /etc/syslog-ng/syslog-ng.conf or /etc/syslog-ng/syslog-ng.conf.in (preffered) on ServerB, ServerC

#
#Added by DShah 05/25/2011
#
destination logserver {
udp("192.168.1.5" port(514));
#Note: here 192.168.1.5 is an IP add of LogServer i.e ServerA
};

log {
source(src);
destination(logserver);
};

Now run the command
#SuSEconfig --module syslog-ng --> to reload the config changes done

#/etc/init.d/syslog restart OR
#syslog-ng restart

#ps aux|grep syslog --> to check if syslog-ng is running

ServerA should be already collecting the log files. You can go to /var/log/HOSTS directory on ServerA to see the log files from different Network Servers.

Illustration by Additional applications:
Let's say I want remote asterisk server to dump it's log file /var/log/asterisk/full in the centralized log server
Edit /etc/syslog-ng/syslog-ng.conf or /etc/syslog-ng/syslog-ng.conf.in (preffered) on remote Asterisk Server

#
# Added by DShah
#
source asterisklog { pipe("/var/log/asterisk/full");
};

destination logserver { udp("192.168.1.5" port(514));
};

log { source(asterisklog); destination(logserver); };

and run the command

#syslog-ng restart

Now please check /var/log/HOSTS , you should see log file from asterisk server.

If you need any help on Linux/Unix systems, you can email me at erdevendra@gmail.com with subject title rapidtechguide.

For more info: http://www.novell.com/coolsolutions/feature/18044.html
20 minutes video on syslog-ns : http://www.balabit.com/network-security/syslog-ng/opensource-logging-system/overview#
Syslog-ns to collect apache logs: http://peter.blogs.balabit.com/2010/02/how-to-collect-apache-logs-by-syslog-ng/

SCREEN command: Handy tool for multi-screen session and remote interaction

2011-04-04T23:50:00.000-07:00

Screen is the Multi-Screen utility that allows the users to access the multiple screen in single SSH session that allows user to do different tasks on different screens. User doesn't require to open multiple SSH session. However, you need to learn some keyboard short-cuts.

How to start Screen?
# screen -S mySessionName

e.g screen -S rapidlinux

Common screen commands

screen command	Task
Ctrl+a c	Create new window
Ctrl+a k	Kill the current window / session
Ctrl+a w	List all windows
Ctrl+a 0-9	Go to a window numbered 0 9, use Ctrl+a w to see number
Ctrl+a Ctrl+a	Toggle / switch between the current and previous window
Ctrl+a S	Split terminal horizontally into regions and press Ctrl+a c to create new window there
Ctrl+a :resize	Resize region
Ctrl+a :fit	Fit screen size to new terminal size. You can also hit Ctrl+a F for the the same task
Ctrl+a :remove	Remove / delete region. You can also hit Ctrl+a X for the same taks
Ctrl+a tab	Move to next region
Ctrl+a D (Shift-d)	Power detach and logout
Ctrl+a d	Detach but keep shell window open
Ctrl-a Ctrl-\	Quit screen
Ctrl-a ?	Display help screen i.e. display a list of commands

Play with above listed commands. Once you are comfortable with those commands, let's learn one more thing: REMOTE INTERACTION

Scenario: Let's say you SSHed into your client's machine. Your client want to see what commands you are running. You can do that via SCREEN :)

1. SSH into client's machine with your support user ID on client's machine.
e.g #ssh rapidsupport@client.machine

2. Run Screen command with session name
e.g #screen -S rapidsupportSession

3. You have to allow multiple user access in screen session. So, Press Ctrl + a followed by :multiuser on

4. You have to grant permission to client to access your screen session. So, Press Ctrl + a followed by :acladd clientname where clientname is the client's user ID

5. Now client can connect to your screen session using the command syntax #screen -x username/session

e.g #screen -x clientname/rapidsupportSession

6. Now your screen is shared with your client.

Done!!!!

Let's say ur client's machine is behind NAT (i.e client's machine doesn't have public IP ) and you want to provide remote support to your client. Your workstation should have public IP address to support it as ur client.

We can use Reverse SSH to achieve that.

To permit you to access your client's machine through Reverse SSH (Secure Shell protocol), client should execute the following command as root user (superuser) on his machine:

Example:

#ssh -fN -R 5099:localhost:22 rapidsupport@public-ip-address-of-rapidsupport -p 443

where, rapidsupport is an user id on your workstation

If successful, this command will set up an SSH tunnel between client's machine and rapidsupport's workstation, and will display a new command-line prompt on your server.

Note: This method of connecting is called "reverse" SSH because the connection is initiated from client's machine, not from rapidsupport.

Now, rapidsupport can SSH in client's machine using credential of client's machine.

#ssh localhost -p 5099

For more:

http://www.linux.com/archive/feed/56443
http://www.cyberciti.biz/tips/linux-screen-command-howto.html

VLAN : 5 mintue reading to get the core concept of VLAN implementation

2011-03-08T21:23:00.000-08:00

VLAN (Virtual LAN) is the logical technique that enables hosts across various LANs to communicate with each other as if they are on same LAN/wire.

VLAN splits the broadcast domain as host on one VLAN can't talk with host on another VLAN without the help of Layer 3 device.

There are two types of the switch port operation mode:

Trunk Mode: Allows multiple VLAN ID to pass through; Usually FastEthernet 0/24 port or GigabitEthernet port for inter-switch link. Multiple switches are interconnected via link connected to the port in Trunk mode.

Access Mode: Allows only one VLAN ID; Hosts are connected to the ports defined as Access mode. By default all ports on the switch are in Access Mode.

Let's see how to define VLAN, add interface/switch ports to VLAN and define TRUNK port

[ In this example we have FinanceDept and HumanResourceDept and we want to separate them using VLAN]

>en
Switch#config term
Switch#hostname Switch1

Switch1-config# vlan 2
Switch1-config-vlan#name HumanResourceDept

Switch1-config-vlan#vlan 3
Switch1-config-vlan#name FinanceDept

Switch1-config-vlan#exit
Switch1-config#exit

Switch1#show vlan
(Find which ports are being used by HumanResourceDept hosts and FinanceDept hosts; say F0/1,F0/2 are being used by HumanResourceDept hosts and F0/3 and F0/4 are being used by FinanceDept hosts)

Switch1#config term
Switch1-config#int F0/1
Switch1-config-if#switchport access vlan 2
Switch1-config-if#int F0/2
Swtich1-config-if#switchport access vlan 2

Switch1-config#int F0/3
Switch1-config-if#switchport access vlan 3
Switch1-config-if#int F0/4
Swtich1-config-if#switchport access vlan 3

Switch1-config-if# [press Ctrl + z]
Switch1#

Now check, if F0/1 and F0/2 are assigned to VLAN 2 , similarly check if F0/3 and F0/4 are assigned to VLAN 3

Switch1#show vlan

Now, hosts belonging to HumanResourceDept connected to Port F0/1 and F0/2 should be able to talk to each other. Perfom ping test.
Similarly do the test with FinanceDept hosts

VERY VERY IMPORTANT CONCEPTS:
>> Hosts on same vlan *must* has same subnet number. For example HumanResourceDept hosts should be under same subnet e.g 192.168.1.0/24 like Host1 IP: 192.168.1.2/24 Host2 IP: 192.168.1.3/24

>> Layer 3 device is required to establish communication between different VLANs

Now, lets define Trunk port on Switch1 so that we can interconnect it to another switch Switch2.

Switch1#config term
Switch1-config#int F0/24
Switch1-config-if#switchport mode trunk

Switch1-config-if# [Press Ctrl + z]

Switch1#show interface trunk

[This will show that F0/24 passes all the VLAN from one switch to another switch. Thus TRUNK mode is only enabled on FastEthernet port and GigabitEthernet port as it requires high bandwidth to pass all VLAN]

Do the same on Switch2

Switch>en
Switch#hostname Switch2

Switch2#config term
Switch2-config#int F0/24
Switch2-config-if#switchport mode trunk

Switch2-config-if# [Press Ctrl + z]

Switch2#show interface trunk

Let's say there is one host of FinanceDept plugged in on port F0/10 of switch2. For the hosts of FinanceDept on switch1 to talk with host on switch2, you have to define VLAN on switch2 and add the desired access port (here in our example: it's port F0/10 on that vlan 3).

Switch2#config term
Switch2-config#int F0/10
Switch2-config-if#switchport access vlan 3

Now, perform ping test between hosts of FinanceDept plugged in to Switch1 and Switch2. [ Friendly reminder: Hosts on same vlan should have same subnet number.]

Console Port Connection in Cisco Routers

2011-02-14T08:44:00.000-08:00

The router has an EIA/TIA-232 asynchronous serial console port (RJ-45). Depending on the cable and the adapter used, this port appears as a DTE or DCE device at the end of the cable.

For connection to a PC running terminal emulation software e.g HyperTerminal in Windows machine, router is provided with an RJ-45 to DB-9 adapter cable (blue cable).

The default parameters for the console port are 9600 baud, 8 data bits, 1 stop bit, and no parity. The console port does not support hardware flow control.

For general overview of Hardware installation and Software configuration, please go thru' following links:

Hardware Installation

Software Configuration with upgrade techniques

Update JAVA and Install NetBeans in Mac OS X 10.5

2011-02-06T14:13:00.000-08:00

Mac OS X:
Check Mac OS X version by executing
> sw_vers
ProductName: Mac OS X
ProductVersion: 10.5.8
BuildVersion: 9L31a

Version 10.5.x

Java Version:
Check Java version in your system by executing

>java -version
java version "1.5.0_13"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_13-b05-237)
Java HotSpot(TM) Client VM (build 1.5.0_13-119, mixed mode, sharing)

This is J2SE 5.0

[On the top right corner, there is spotlight/search. Search for "Java Preferences". Open that application. It allows you to select/de-select various versions of Java in your system ]

Our task: Update J2SE 5.0 to Java 6 [ Java SE 6] :
[ Java replaced name J2SE with Java SE starting from version 6 ]

Step 1: Go to http://support.apple.com/downloads/ and search for " java for mac os x 10.5 "

Step 2: Download the Java for Mac OS X 10.5 update 4
http://support.apple.com/kb/DL848

Java for Mac OS X 10.5 Update 4 delivers improved reliability, security, and compatibility for Java SE 6, J2SE 5.0 and J2SE 1.4.2 on Mac OS X 10.5.7 and later. This release updates Java SE 6 to version 1.6.0_13, J2SE 5.0 to version 1.5.0_19, and J2SE 1.4.2 to 1.4.2_21.

Check java version:

>java -version
java version "1.6.0_13"
Java(TM) SE Runtime Environment (build 1.6.0_13-b03-211)
Java HotSpot(TM) 64-Bit Server VM (build 11.3-b02-83, mixed mode)

Step 3: Download the Java for Mac OS X 10.5 update 5
http://support.apple.com/kb/DL924

Caution: After installation of update 5, you have to restart the system.

Java for Mac OS X 10.5 Update 5 delivers improved reliability, security, and compatibility for Java SE 6, J2SE 5.0 and J2SE 1.4.2 on Mac OS X 10.5 .8 and later. This release updates Java SE 6 to version 1.6.0_15, J2SE 5.0 to version 1.5.0_20, and J2SE 1.4.2 to 1.4.2_22.

Check Java Version:

>java -version
java version "1.6.0_15"
Java(TM) SE Runtime Environment (build 1.6.0_15-b03-226)
Java HotSpot(TM) 64-Bit Server VM (build 14.1-b02-92, mixed mode)

Step 4: Download the Java for Mac OS X 10.5 update 8

http://support.apple.com/kb/DL971

Java for Mac OS X 10.5 Update 8 delivers improved compatibility, security, and reliability by updating J2SE 5.0 to 1.5.0_26, and updating Java SE 6 to 1.6.0_22 for 64-bit capable Intel-based Macs . J2SE 1.4.2 is no longer being updated to fix bugs or security issues and remains disabled by default in this update.

Check Java version
>java -version
java version "1.6.0_22"
Java(TM) SE Runtime Environment (build 1.6.0_22-b04-307-9M3263)
Java HotSpot(TM) 64-Bit Server VM (build 17.1-b03-307, mixed mode)

After updating Java from J2SE 5.0 to Java SE 6.0 with latest updates, we are now ready to install NetBeans ( IDE for Java,C,PHP.. more Programming)

Go to http://netbeans.org/downloads/index.html
and download your desired bundle for the Mac OS. It has pretty neat chart showing the NetBeans IDE support integration.

Since I am going to do basic Java SE programming, I will download very basic NetBeans IDE.

Install the downloaded .dmg file for NetBeans IDE and you are good to go.

[I have assumed that you know how to install the download .dmg file for Mac. It's easy. Just double click the respective downloaded .dmg file, the wizard will automatically walk you through the installation process]

How e-mail works? .. even a caveman can understand, yes even a caveman

2010-10-10T17:35:00.000-07:00

SMTP (Port 25): handles outgoing mail

POP3/IMAP (Port 110/143): handles incoming mail

Let's have scenario: John Doe at hotmail.com is sending email to Laura Johnson at gmail.com. John Doe is using Outlook to send an email. Laura is using web for gmail.com.

(Outlook, web interface are the front end for the users. They are just the GUI interface)

John uses Outlook--> send email from Hotmail.com account to Laura Johnson having Gmail.com account--> Laura checks email at www.gmail.com

1. Outlook connects to SMTP server at hotmail.com using Port 25

John writes an email to Laura

From: John.Doe@hotmail.com

To: Laura.Johnson@gmail.com

Subject: Hi Laura

Body: Hi Laura, How are you? What's your plan for this weekend? Let's go to the state fair at Dallas.

2. SMTP server at hotmail.com reads "TO" field and breaks it into two parts e.g Laura.Johnson@gmail.com is broken into "Laura.Johnson" and "gmail.com"

3. SMTP server at hotmail.com queries to DNS server; Who is SMTP server at gmail.com?

DNS server looks into MX records and replies back with one or more SMTP servers at gmail.com

4. SMTP server at hotmail.com connects to one of the SMTP server at gmail.com and handles the message. SENDMAIL and POSTFIX are the most popular MTA (Mail Transfer Agent) to deliver mail from one SMTP server to another another SMTP server. My preference is POSTFIX as it's free, easy, secure, customizable and popular too.

5. SMTP server at gmail.com recognizes that "Laura.Johnson" is the user at gmail.com and it handover the message to gmail POP3/IMAP server which puts the message in the Laura.Johnson's INBOX.

6. Laura logs in to www.gmail.com and checks her email.

It's that easy. Remember, we didn't talk about handling the junk emails.

It goes little bit complex for handling the junk emails. Please google about that if you want to know more...

Extra Treat:

SMTP commands:

HELO

EHLO

MAIL FROM

RCPT TO

DATA

RESET

QUIT

HELP

VRFY

EXPN

VERB

POP3 commands:

USER

PASS

QUIT

LIST

RETR

DELE

TOP

How can I setup VLAN on my Windows XP or Workstation?

2010-10-06T09:07:00.000-07:00

If you have Intel NIC card, you are lucky. Intel PROset utility/driver allows you to add/remove VLAN on your workstation.

You could download Intel PROset from http://downloadcenter.intel.com/
Go to Downloads and Drivers and search for Intel PROset and choose your operating system

Install the downloaded executable file
(While installing it will prompt if you want to use MMC for the management, select YES)

It will also ask if you want to remove old drivers and settings, you can say NO

Once it is installed, Right Click "My Computer" --> Manage --> Device Manager --> Network Adapters --> Right Click "Inter(R) XXXX whatever it shows " --> Properties --> VLAN and add your desired VLAN ID

Try to access other devices on the same VLAN. It should work. If not contact your network administrator.

Other TIPS:
1. Start --> Run --> winmsd

if Processor properties has x86, your OS is 32 bit
if Processor properties has ia64, your OS is 64 bit

2. Device manager will show you the vendor of your NIC card. It could be Realtek, INTEL, Broadcom. The above procedure for VLAN will only work for INTEL NIC.

Remote Desktop in console mode

2010-10-04T05:30:00.001-07:00

If you are using Windows XP RDP client, for RDP in console mode

mstsc /console

If you are using Windows Vista or above, it doesn't use /console session, it uses /admin session

mstsc /admin

Rename multiple files in Linux

2010-09-23T03:47:00.000-07:00

Lets' change all files with extension ‘.html’ to ‘.php’.

Rename all *.html files in one folder

rename

#rename .html .php *.html

Do the same operation recursively in a directory tree

find . -name "*.html" -exec rename .html .php {} \;

Those double quotes around *.info are important

If you want to be expert go to following link and don't forget to read all the comments :)
http://www.thegeekstuff.com/2009/06/how-to-rename-files-in-group/

Basic tutorial on Logrotate

2010-08-30T05:56:00.000-07:00

Log files in Linux usually reside at /var/log... It keeps on growing so log management is essential. Log management is usually achieved using logrotate. Logrotate is managed by cronjobs in Linux.

For logrotate, you can configure /etc/logrotate.conf or create the individual configuration files for each application or each log file in /etc/logrotate.d

step 1:

Let's say, I have VOIP application 'asterisk' running on my system. Asterisk generates various log files under /var/log/asterisk directory. I would create astlog under /etc/logrotate.d to manage the log files.

#cd /etc/logrotate.d
#vi astlog
/var/log/asterisk/full /var/log/asterisk/messages /var/log/asterisk/debug /var/log/asterisk/*.log {
nocompress
daily
rotate 5
missingok
copytruncate
}

Here we listed all the log files to be managed and provided the attributes of the log management. Don't compress the log file, rotate the log file daily, max number of log rotation 5 ( i.e logfilexxx.1, logfilexxx.2, .... , logfilexxx.5). It only keeps 5 log files. With copytruncate option, the original log file is truncated in place after creating a copy, instead of moving the old log file and optionally creating a new one. It is useful when some program cannot be told its logfile and thus might continue writing(apending) to the previous log file.

[you can use #stat < filename > or # ls -l < filename > to check the inode number
copytruncate helps the log file to preserver it's inode(unique file number) ]

If you don't want to use copytruncate option, then you have to tell the program that log file has been recreated (with new INODE number). For example, in my case I could have done

#cd /etc/logrotate.d
#vi astlog
/var/log/asterisk/full /var/log/asterisk/messages /var/log/asterisk/debug /var/log/asterisk/*.log {
nocompress
daily
rotate 5
missingok
create

        postrotate
             /usr/sbin/asterisk -rx 'logger reload' > /dev/null 2> /dev/null
 endscript

}

Here, we are telling our program 'asterisk' to reload logger as new log file has been created after log rotation.

step 2:

By default, Logrotate is scheduled daily. You can find 'logrotate' under /etc/cron.daily

Let's look at /etc/crontab

# less /etc/crontab
SHELL=/bin/sh
PATH=/usr/bin:/usr/sbin:/sbin:/bin:/usr/lib/news/bin
MAILTO=root
#
# check scripts in cron.hourly, cron.daily, cron.weekly, and cron.monthly
#
-*/15 * * * * root test -x /usr/lib/cron/run-crons && /usr/lib/cron/run-crons >/dev/null 2>&1

The time to execute the scripts is managed by crontab. /usr/lib/cron/run-crons script controls the cron.hourly, cron.daily, cron.weekly and cron.monthly. run_crons runs every 15 minutes and ensures that cron jobs are taken care of.

In SLES, if you need to change the default daily time , you can go to YAST --> System --> /etc/sysconfig editor --> System --> Cron --> DAILY_TIME and change the time.

Let's say, I want logrotation to be done at OFF hours (10:30 pm) to avoid the possible load on the server, then, I can change DAILY_TIME to 22:30

Tips:

To run the logrotate manually, you can try
#logrotate astlog

For more information:

http://www.linuxtopia.org/online_books/suse_linux_guides/SLES10/suse_enterprise_linux_server_installation_admin/sec_suse_pakete.html

http://www.thegeekstuff.com/2010/07/logrotate-examples/

CAT3 vs CAT4 vs CAT5 vs CAT5e vs CAT6

2010-07-13T07:25:00.000-07:00

CAT3- contains 4 pairs of wires and can carry up to 10Mbps with a possible bandwidth of 16MHz. (UTP)

CAT4- contains 4 pairs of wires and can carry up to 16Mbps with a possible bandwidth of 20MHz. (UTP)

CAT5- contains 4 pairs of wires and cancarry up to 100Mbps with a possible bandwidth of100MHz. However there is more than one variety. There is also FastCAT which has a possible bandwidth of up to 350MHz. (UTP)

CAT5e- a higher grade of CAT5 that contains high-quality copper, offers a higher twist ratio (to eliminate cross-talk) and can support a bandwidth of 200MHz (2x that of REGULAR CAT5) (UTP)

CAT6- a twisted pair cable that contains 4 wire pairs each wrapped in foil insulation (to eliminate cross-talk). Additional foil covers the bundle of wires (to eliminate cross-talk further, and shield it from other interference ie. EMF from flourescent lights) and a fire-resistant plastic sheath covers the second foil layer. CAT6 supports at least six times the throughput of regular CAT5, but it is also 3-4x the price of CAT5. (STP)

UTP=Unshielded Twisted Pair
STP=Shielded Twisted Pair

Make copy batch file in windows

2010-05-28T07:37:00.000-07:00

If you need to make a copy of your local drive to the backup drive scheduled everyday, you will need to know couple of things. [I am talking on Windows environment ;) ]

1. Download the robocopy. It is one of the microsoft product. It stands for robust copy

This is well built GUI tool. However to understand the various options available, you can check this
http://ss64.com/nt/robocopy.html

2. Install robocopy. You can write the simple script to make the copy process. [ You can use any kind of editor like notepad, wordpad, notepad++ to write the script]

robocopy source_folder destination_folder [file(s)_to_copy] [options]

#
# Script file name: C:\mycopy.cmd
#
@echo "Copying files and folders"
robocopy "C:\myLocalFile" "F:\myBackup" /E

@echo "Copy process completed"

/E  option allows to Copy Subfolders, including Empty Subfolders


3. Finally you can schedule the command file(batch file)
created by you to run in the specific time. 
Go to Control Panel --> Scheduled Tasks -->
Right click and create a new schedule task -->
Give the name to it --->
Right click on the scheduled task created and go to the properties -->
specify the path of the script file in the run section under Task Tab
(in my case it would be C:\mycopy.cmd ) -->
Now go to the Schedule Tab and specify the schedule you wanted

Hey you are done.

Etherpad installation on SLES or CentOS

2010-04-18T12:53:00.000-07:00

Etherpad is online real-time collaborative document editing tool.

Requirements:

Java 1.6
Scala 2.7
MySQL Server 5.1
mysql-connector-java
etherpad (If you need already cooked etherpad, feel free to ask me. I will email you)

Steps to be followed:

1. Create username 'etherpad' with password 'password'

#useradd -r -m etherpad
#passwd etherpad

2. Install MySQL and configure MySQL

--> You can use YAST for SLES and YUM for CentOS

#service mysql start --> in SLES
#service mysqld start --> in CentOS
#chkconfig mysql on --> to enable MySQL on next reboot

3. Once you download Scala 2.7 , extract the tar file to the /usr/local/scala directory.

#mkdir /usr/local/scala
#cd /usr/local/scala
#tar xvzf scala-2.7.7.final.tgz

4. Once you download mysql-connector-java, extract the tar file to the /usr/local/mysqlconnector

#cd /usr/local
#tar xvzf mysqlconnector.tar.gz

5. Install JAVA 1.6

#sh jdk-6u20-linux-x64-rpm.bin

Use YAST or YUM to install "fastjar"

6. Create myENV file

#touch myENV
#vi myENV
export JAVA_HOME=/usr/java/jdk1.6.0_20/
export JAVA=$JAVA_HOME/bin/java
export SCALA_HOME=/usr/local/scala/scala-2.7.7.final/
export SCALA=$SCALA_HOME/bin/scala
export PATH=$JAVA_HOME/bin:$SCALA_HOME/bin:$PATH
export MYSQL_CONNECTOR_JAR=/usr/local/mysqlconnector/mysql-connector-java-5.1.12-bin.jar

7. /etc/profile hosts the environment variables

#cat myENV >> /etc/profile

Logout and log back in.

8. Create database called "etherpad" and grant privilege to user "etherpad"

#mysql
>create database etherpad;
>grant all privileges on etherpad.* to 'etherpad'@'localhost' identified by 'password';
>exit;

9. Extract the content of etherpad in /etherpad directory.

#cd /etherpad/trunk/etherpad
#cd /bin
#vi rebuildjar.sh
We need to modify rebuildjar.sh as it fails to find the location of 'Infrastructure' directory

Change
source ../infrastructure/bin/compilecache.sh
to
source ../../infrastructure/bin/compilecache.sh

Change
cd ../infrastructure
to
cd ../../infrastructure

Also modify some other files

etherpad/trunk/etherpad# cp etc/etherpad.localdev-default.properties bin/data/etherpad.local.properties

etherpad/trunk/etherpad# cat bin/data/etherpad.local.properties
ajstdlibHome = ../../infrastructure/framework-src/modules
appjetHome = ./data/appjet
devMode = false
etherpad.adminPass = password
etherpad.fakeProduction = false
etherpad.isProduction = true
etherpad.SQL_JDBC_DRIVER = com.mysql.jdbc.Driver
etherpad.SQL_JDBC_URL = jdbc:mysql://localhost:3306/etherpad
etherpad.SQL_PASSWORD = password
etherpad.SQL_USERNAME = etherpad
listen = 127.0.0.1:9000
logDir = ./data/logs
modulePath = ../src
transportPrefix = /comet
transportUseWildcardSubdomains = true
useVirtualFileRoot = ../src

Also need to modify 3 other files

# vi etherpad\trunk\etherpad\src\etherpad\globals.js

var SUPERDOMAINS = {
'localbox.info': true,
'localhost': true,
'127.0.0.1': true
};

#vi etherpad\trunk\etherpad\src\etherpad\pro\pro_utils.js

var fromDomain = '127.0.0.1';

#vi etherpad\trunk\etherpad\src\main.js

var newurl = "http://127.0.0.1"+request.path;

10. Now we are almost done.
[it is very important that you are inside bin directory of etherpad to run the script files, otherwise you will get error: file location not found or something wrong]
etherpad/trunk/etherpad# cd bin
etherpad/trunk/etherpad/bin# ./rebuiljar.sh
etherpad/trunk/etherpad/bin#./run-local.sh

12. Then go to http://127.0.0.1:9000, it will prompt you to create new pad

13. To customize the home page, you can edit the file
# vi etherpad\trunk\etherpad\src\templates\main\home.ejs

14. If you replace 127.0.0.1 with your server IP address in all the files mentioned above, you can access Etherpad using http://your-ip-address:9000/

Links:
http://code.google.com/p/etherpad/wiki/Instructions
http://pauleira.com/13/installing-etherpad/
http://karteek.selfdabba.com/post/301488675/etherpad-opensourced

CVS and CVSNT in glance

2010-04-14T06:20:00.000-07:00

1. Create Repository on the CVSNT server.

2. Launch wincvs and navigate to Admin --> Preferences --> specify CVS HOME [it is any directory that might be needed for wincvs configuration, however you will not need it if you are beginner]. If you have installed WinMerge or File Compare Tool (powerful), you can select that as your External Diff program. If you have Notepad++ installed, you can select that as your default editor.

3. Import module into the Repository (it means importing the Local project directory into the Repository)
a> Before importing module, we need to browse the local directory from wincvs [ see the browse section at the top in toolbar section]
b> On left side, you will see your local project directory which you just browsed.
c> Right click the folder and select Import Module option
d> Ignore the files which you can't edit [ e.g. .rpm, .bak, .pub and many more]
e> Specify the CVSROOT and repository location
f> You might want to tell wincvs to create CVS hierarchy so that it can create versions of files.

4. You can start editing files [Remember: When you are editing files, you are editing in your local project folder, no in the repository]. Once you are done, you can commit the changes. Commiting the changes means to make the change on the Repository too. Once the change is done on repository, you can checkout the module [ your project ]. Checkout means pulling out the project from the repository.

[local project directory] ------import--> [Repository] -----export--> [checkout project directory]

Change UUID of virtual drive

2010-03-28T11:09:00.000-07:00

I made a copy of virtual drive (by copy and pasting .vdi file). Then, I tried to mount the .vdi file in the virtual machine. It came up with some error: A hard disk with UUID {bla..bla..bla......} is already registered. So, I was unable to mount the drive.

Now, what is the solution?
Ans: Change the UUID of the virtual/image drive.

How can I change the UUID of the virutal drive?
Ans: You have to run the VBoxManage command

[Before running command, make sure that environment variable is set to the location of the virtual box commands. To set environment variable: Go to "My Computer" --> Right click --> Properties --> Advanced --> Environment Variables --> Add the location of Virtual Box to the PATH variable; In my case it is : PATH .......;C:\Program Files\Sun\VirtualBox ]

C:\ > VBoxManage internalcommands setvdiuuid disk2.vdi

[disk2.vdi is the name of my copied .vdi file]

Now, try to mount the disk2.vdi in Virtual Machine.
Have a good one!

On my second day, I found issue with SLES (Suse Linux). It keeps on complaining "VB is waiting for /dev/disks/by-id/scsi-xxxxx-part2 to appear".
After some research on blogs, found that GRUB in SLES looks for UUID of disk to boot.

I set the copied/cloned harddisk as second harddisk (primary slave) for the original SLES VM. Then I startet the original SLES VM.
In the running SLES VM I made a new directory and mounted it to the root directory of the cloned harddisk.
Then I startet (as root) the Yast partition manager and noticed the UUID of the cloned harddisk. (It is made from the UUID shown with vboxmanage list hdds, but it is not the same).
Then I edited (as root) the /boot/grub/menu.lst and the /etc/fstab : I changed the UUID everywhere the old one was (do not use capital letters instead of small letters).
Now shutdown (after unmounting the cloned root directory)
Then I disabled the cloned harddisk as second harddisk in the original VM and set it as first harddisk in the cloned VM.
Starting the cloned VM now works.

For Network cards to work you have to do

rename the ifcfg-eth-id- to ifcfg-eth0 (in /etc/sysconfig/network)
remove the rules file (/etc/udev/rules.d/30-
edit /etc/sysconfig/network/config and change FORCE_PERSISTENT_NAMES to "no".

Install VMware-tools

2010-03-27T16:20:00.000-07:00

It might be challenging to install VMware-tools if we don't know what exactly we are doing.
You need to read all the instructions that is provided by VMware workstation or Virtual Center or ESX server.
For now, I am going to give the instruction for Linux systems.
After installing Linux as Virtual Machine on the top of VMware workstation/ESX Server or VSphere (whatever), you will see that VMware-tools is not installed.

Steps to be followed:

1) Choose "Install VMware tools" from VM menu

2) You will recognize some change on "cd-rom" icon located at Left corner of VM. It just like someone has inserted the CD of VMware tools in your VM.

3) Now you need to mount the CD-ROM so that you can access the contents.
#mount /dev/cdrom /mnt/cdrom
If you are lucky, above command will work without any issue. If not you might have to specify some mount options like
# mount -o ro /dev/cdrom /mnt/cdrom
(which mean mount as read-only option)
Some systems requires you to specify the file-systems type. FYI, CD-ROM uses iso9660 file-system
# mount -t iso9660 -o ro /dev/cdrom /mnt/cdrom

4)After this, go to /mnt/cdrom directory. You will find VMware-toools over there. You can install from RPM or TAR file. It all depends on you, however I recommend tar file.

# cd /mnt/cdrom
# rpm -ivh [VMware-tools......rpm]

or
# cd /mnt/cdrom
#tar -xvzf [VMware-tools.......tar] /root/vmware
(this will un-archive the "tar" file under /root/vmware directory
# cd /root/vmware
#./vmware-install.pl

Some slick Unix/Linux commands... much more powerful and useful

2010-03-09T05:16:00.000-08:00

KILL

usage:

Kill process by Process ID

kill -9 [PID] --> Forcefully Kill
kill -15 [PID] --> Gracefully Kill
kill %[JobID] --> JobID can be checked by command #jobs

Kill process by Process Name

killall [proces name]

PID/Process name can be found using commands like

ps -aux
ps -elf
netstat -anp
lsof -w -n -i [tcp/udp:port number]

System Tuning Commands:

#mpstat -A ALL --> CPUs status

#top --> Press 'I' to toggle between Irix Mode (Irix Mode display resource usage mulitplied by total number of CPUs) ; Press "1" to see all the CPUs

# sar

Networking Commands

#netstat -anp --> Where 'p' flag shows which program is making connection

[ Hey, now I know which program is making a connection, can I use kill command to kill by process name or PID? Answer: Ofcourse, that's the reason I am writing this article ]

Now you know how to terminate the particular remote connection in the server. There is also another technique using #lsof.

# lsof -w -n -i tcp:22

This command will display all the SSH (tcp:22) connections. So, you can see who has intruded in your system using SSH. This will also give process ID (PID) or process name, which you can terminate using KILL command.

[ use man page for each command in details]

#ifstat

#ethtool [ethernet interface name] --> this command can used to see if the interface is physically down or not

e.g # ethtool eth1

#netstat -i

#netstat -s

To get the BIOS information

#dmidecode

To list the hardware

#hwinfo

#lshw

[Note: lshw is not the linux project. If you want to use lshw, you have to download and install the RPM for that command http://ezix.org/project/wiki/HardwareLiSter ]

Bash Script to collect system information:

This is one of the simple script file to pull basic and informative information about your server:

#********************

#ServerReport.sh

# Created by DShah

# Please use it at your own risk

#********************

#!/bin/bash
miniDivider(){

echo "*******************************************************************";
}

serverInfo() {

uname -a
cat /etc/*release

}

diskInfo() {

# fdisk -l
df -h
iostat

}

memoryInfo() {

free -m
vmstat

}

cpuInfo() {

mpstat
mpstat -P ALL

}

overallInfo() {

top -b -n2

}

networkInfo() {
netstat -s
miniDivider

sleep 2
netstat -s
}

dividerLine(){

echo "########################################################################";

echo "########################################################################";

}

fileName="serverReporting.txt"

rm $fileName
touch $fileName

echo "ServerInfo Reporting"
serverInfo >> $fileName
dividerLine >> $fileName

echo "DiskInfo Reporting"
diskInfo >> $fileName
dividerLine >> $fileName

echo "MemoryInfo Reporting"
memoryInfo >> $fileName
dividerLine >> $fileName

echo "CPUInfo Reporting"
cpuInfo >> $fileName
dividerLine >> $fileName

echo "Network Info Reporting"
networkInfo >> $fileName
dividerLine >> $fileName

echo "Top command reporting";
overallInfo >> $fileName

Port Forwarding Rule Setup in Actiontec router (VZ WIRELESS ROUTER)

2009-12-27T16:19:00.000-08:00

First of all login in router access page; most often it is http://92.168.1.1

In my case

public IP: 72.B.C.D (I haven't provied my public ip for my privacy)
private IP: 192.168.1.x

Step: 1 Click on Firewall Setting--> Port Forwarding --> New Entry

step: 2 Give the device name (LAN device) where your outer world need to have access; for e.g Web server in LAN hosted on computer named as 'windows' with IP add 192.168.1.16

step 3: We selected "Forward to Port : User Defined " so that we can customize the way (I mean the Port) we can access LAN service from outside world. I named my WebServer application as DevApp.

step 4: Now configure the service/Application. The simplest rule would be: Any one can access through the my defined Port (say 8081) using TCP protocol

step 5: now we should select OK

step 6: Forward to Port : the port where my web server is listening. In my case my web server is listening at 192.168.1.16:8081 (FYI - Listen port can be changed in httpd.conf e.g Listen 192.168.1.16:8081)

step 7:

step 8: Once the rule is defined, it should be refreshed in router or applied.

step 9: Click Refresh/Apply

My Guest OS cannot ping My Host OS in Virtual Box

2009-10-11T22:30:00.000-07:00

The default networking setup for VirtualBox is NAT, which means basically that your host computer is acting like a router, creating a virtual network for your virtual machine to connect to. Naturally, this network has it's own IP scheme.

I have a router(gateway) 192.168.1.1 (255.255.255.0)
host computer 192.168.1.5

I was trying to manually set up my guest to static ip 192.168.1.12 and found it cannot ping my gateway, neither can access internet.
By default the ip of guest is 10.0.2.15, it can access internet and my router(192.168.1.1)

To fix the issue, I had to use Bridge Network.
1) Virtual Box -> SETTINGS -> NETWORK -> Bridge -> Edit Setting -> Add your active adapter for internet/network (in my case I am using Wireless Adapter en1: AirPort of my MacBook )

2) Then I started my guest OS. Say I have Windows XP as my guest OS. I need to edit the network settings. Manually add the IP ADD, DEFAULT GATEWAY, DNS. Since my router act as DNS for my LAN, I used DNS same as my DEFAULT GATEWAY.

HACMP

2009-05-22T11:26:00.001-07:00

http://publib.boulder.ibm.com/infocenter/tivihelp/v2r1/index.jsp?topic=/com.ibm.itame.doc_5.1/am51_webinstall338.htm

System Administrator's Role

2009-04-17T07:06:00.000-07:00

System Administrator's Role: (BASIC ROLES)

Preinstallation planning
Install - hardware, software, network
Manage - user accounts, system resources, licenses
Backup/recovery
Define subsystems
Performance monitoring, capacity planning

SAN Requirements:

IBM DS8300 frame
SVC (SAN Volume Controller)
EMC Symmetrix 8830
EMC Clariion CX700 & CX300
Cisco and Brocade Switches
IBMs TSM (Tivoli Storage Manager) and TPC (TotalProductivity Center)

Some fundametals and tweaks in AIX

2009-04-17T06:36:00.000-07:00

Default Multi-user runlevel in AIX : runlevel 2

To bring down system in Maintenance mode/Single user mode
#shutdown -m

To bring back system in runlevel 2
#telinit 2

*********************************
SRC ( System Resource Controller) for easy management of group of Deamon/Subsystem in AIX

#lssrc -a
#ps -ef

notice the output of above commands

#stopsrc -s
#startsrc -s
#refresh -s : this command enables deamon to reread any of it's configuration file; so whenever we made any changes in deamon config files, we can use refresh command to bring the changes into effect.

Not all process are controller by SRC/ srcmstr; those process which are not controlled by SRC can be killed by
#kill

*****************************

Manage the System Environment (e.g time, license, characteristics of OS etc)

#smit system

Manage the system language environment

#smit mlang

***************************
SU command:

The su command allows you to assume the permissions of any user whose password you
know.
Every time the su command is used an entry is placed in the file /var/adm/sulog (this is an
ASCII text file). This makes it easy to record access as the superuser. Normal logins are
recorded in the file /var/adm/wtmp. To read the contents of this file use the command:
who /var/adm/wtmp.
The su command can also be specified with the - option. The - specifies that the process
environment is to be set as if the user had logged into the system using the login
command. Nothing in the current environment is propagated to the new shell. For
example, using the su command without the - option, allows you to have all of the
accompanying permission of root while keeping your own working environment.

Boot Image of AIX

2009-04-17T05:57:00.000-07:00

Using Bootlist from System ROS/BIOS/EFI (whatever you say) , System locates the boot device and attempts to load the Boot Image of OS to the Memory. So, the question comes: What is the Boot Image?

Boot image of AIX contains the files required to boot the AIX system, including the AIX kernel, the RAMFS (RAM file system), and the copy of Base ODM (Object Data Manager)

ROS : Read Only Storage
BIOS : Basic Input Output System
EFI : Extensible Firmware Interface

System Initialization in Brief:

In General
Hardware Initialization -- Low Level Configuration -- Load Boot Image -- AIX Initialization

For POWER servers:
System ROS ---- SMS/BOOTLIST ---- Software ROS------ BLV----INIT

For Intel Itanium -based Servers
BIOS/EFI --- Set up EFI boot manager --- EFI system partition contains bootloader boot.efi ---physical partition contains BLV -- AIX Initialization

Startup modes in AIX

2009-04-16T16:25:00.000-07:00

Basically there are 4 startup modes in AIX

1. NORMAL MODE : Multiuser mode; All process are running

2. SYSTEM MANAGEMENT SERVICES : it runs from FIRMWARE and sets bootlist; it's not AIX

3. MAINTENANCE : Singer User mode; password recovery and system recovery for the system which can't undergo normal boot.

4. DIAGNOSTICS : AIX diagnostics

NIM on LINUX for AIX

2009-04-13T11:07:00.000-07:00

Real Good explanation.. seems to be perfect.. but i don't know it will work or not.

http://www.unix.com/aix/44512-nim-linux-machine-real.html

http://www.nasi.com/servers.php

Snapshot : quick magic backup

2009-04-12T20:50:00.000-07:00

Snapshots

This is a very useful feature. Many of us have the situation where important data needs to be backed up, but it cannot be used while the backup is running because then the backed up files would be out of sync with each other. For example, you have an accounting system that is recording orders. The accounts receivable file gets backed up now, and you take an order. Both a/r and the customer file get updated to reflect the new order, but a/r has already been backed up. When the customer file finally makes it to tape, it's not consistent with a/r, and of course it needs to be. Without snapshots, your only recourse is to stop taking orders while the backup runs. If you have lots of disk space, you could copy the whole accounting system and backup the copy, but that can take a lot of time too, and you may not have the space. Snapshots are the solution. Before you do the next step, make sure you've put a few files in /little, and make at least one of them unimportant. Then create the snapshot.

lvcreate --size 200M --snapshot -n mysnap /dev/Volume00/mylv
mkdir /mylvsnap
mount /dev/Volume00/mysnap /mylvsnap
df

Right off the bat you should have noticed something strange. We created mysnap very specifically with a size of 200MB, and trust me, that's all it took away from us, but df shows it being the same size (6GB) as mylv. We'll get back to why this is in a minute, but first take a look at the files in /snap. They are identical to the files in /mylv, right? OK, now go edit a file in /mylv. Does it change in /snap? No, it does not. Remove a file in /mylv - it's still there in /snap. Add a new file to /mylv, and that does NOT appear in /snap. How is this done, and most especially how is it done in 200MB?

It's not magic

OK, it is magic. What is going on is that /snap contains absolutely nothing UNLESS something changes back at /mylv. If you ask for a file from /snap that has not changed, the data is read right from /mylv. But if a file IS changed, before the change is written, the data blocks that don't yet have the changes are written to /snap. Note that entire files are NOT written, just data blocks that are about to change. So, as long as we don't change more than 200MB worth of data in /mylv, we can have our cake and eat it too. Our procedure will be:

Stop using the filesystem, shut down any databases that need to be shutdown etc.
Create the snapshot
Start up our databases, go back to work.
Start backing up /snap

Our time without access is minutes or seconds - just however long it takes to stop the processes and restart them, basically. The backup can take its sweet time. Well it can if it doesn't take so long that we need more than 200 MB to store our data that is changing. That does mean that the size of mysnap does have to be a bit of an educated guess. It also means that as soon as you are done with the backup, mysnap should be removed:

umount /snap
lvremove /dev/Volume00/msnap

If you don't remove it, it will go on copying data as it is changed and eventually it will run out of room. You can't just leave it there for next time!

Some other helpful links:

http://tldp.org/HOWTO/LVM-HOWTO/index.html
http://ds9a.nl/lvm-howto/HOWTO/cvs/lvm-howto/output/lvm-howto.html

http://aplawrence.com/Linux/lvm.html

Backup and Restore

2009-04-09T19:36:00.000-07:00

Tar (Tape Archive)

It's a backup utility to create archive in Tape.

Syntax:
tar [options] [archive name/device name/destination] [files to be archived/source]

options can be : -c create
-v verbose
-x extract
-t show the contents
-z to zip the content

eg. #tar -cvf /dev/st0 /home

Using dump and restore:

dump: it's utility to make a backup of files in ext filesystem

syntax:
#dump [options] [destination] [source]
restore: it's utility to restore a backup

Type of backup:
1. Full Backup --> 0
2. Incremental Backup --> 1-9
e.g #dump -0uf /dev/st0 /home

0--> for full backup
u--> Update the file /etc/dumpdates after a successful dump
f --> Write the backup to file; file may be a special device file like /dev/st0 (a tape drive), /dev/rsd1c (a floppy disk drive), an ordinary file, or - (the standard output)

#dump -1uf /dev/st0 /home

1--> for first incremental backup

RESTORE:

#cd / ; mkdir extract
#cd /extract
#restore -rf /dev/st0

Shell Scripting plus AWK and SED

2009-04-09T16:55:00.000-07:00

Shell Script is series of command written in plain text file. Shell script is just like batch file is MS-DOS but have more power than the MS-DOS batch file

==========================================================
awk utility is powerful data manipulation/scripting programming language (In fact based on the C programming Language). Use awk to handle complex task such as calculation, database handling, report creation etc.

General Syntax of awk:

Syntax:awk -f {awk program file} filename

awk Program contains are something as follows:

Pattern
{
action 1
action 2
action N }

awk reads the input from given file (or from stdin also) one line at a time, then each line is compared with pattern. If pattern is match for each line then given action is taken. Pattern can be regular expressions.

======================================================

SED is a stream editor. A stream editor is used to perform basic text transformations on an input stream (a file or input from a pipeline). SED works by making only one pass over the input(s), and is consequently more efficient.

General Syntax of sed
Syntax:
sed -option 'general expression' [data-file]
sed -option sed-script-file [data-file]

http://freeos.com/guides/lsst/index.html

AIX Backup in short and sweet

2009-03-29T08:54:00.000-07:00

Aix is a unix based os developed by IBM and was originally released in the mid 80s for PC RT. When IBM released the RS/6000 in 1992, it released AIX 3.1 and built in is a mksysb script to do a full rootvg or OS backup. Other volume groups are not touched by this script. It was aimed at scsi tape drives. When booted from tape, the system would be restore rootvg to exactly what it contained when it was backed up. When finished, the system reboots. IBM never supported writing to cd but went directly to dvd. A mksysb can be written to dvd and then booted and restored from dvd. This function would be VERY helpful to linux releases or unix released. What was described earlier is simillar to a product in AIX called Network Install Manager - nim. Using nim, a root user can do a bootable backup to a remote system and then restore from that system. A nim restore is the fastest form of installing AIX and is used by manufacturing to preload systems. Today, at AIX 6.1, nim and mksysb are mature and trusted processes. Non rootvg volume groups are backed up using savevg. savevg is better than tar as it creates logical volumes the correct size and correctly names the mount points and then restores the data. Again, its a mature process. Even open files are backed up with mksysb and savevg although any save to the file after its backed up isn't reflected. A mksysb has 3 components, A boot image, a complete list of files and the actual backup. When the mksysb is taken, it compares what is on the list to what is on the tape in the backup. They must agree.

Another option is LVM snapshot for your system/important directories and then tar/pipe them to lzma (faster/better than bzip2). You can write the scripts yourself or search for somebody else's on google.LVM snapshotting allows you to also capture the logical volumes and only needs the space that the delta data would require. You can back up the snapshot and ensure a consistent state, then destroy the snapshot.

OPEN SOURCE DISASTER RECOVERY SOFTWARE: http://www.mondorescue.org/

You can also try STORIX but it's not free

Ciphering/Encryption

2009-02-01T21:35:00.000-08:00

In RHEL 5.2 we can see SHA-1 being used for the ciphering/encryption. It produces 160 bit digest from a message of width max length: (2^64-1) and based on the principles of MD4, MD5 message digest algorithms.

http://en.wikipedia.org/wiki/Sha1

To view the installed cryptographic ciphers in Linux

#cat /proc/crypto
name : crc32c
driver : crc32c-generic
module : kernel
priority : 0
type : digest
blocksize : 32
digestsize : 4

name : sha1
driver : sha1-generic
module : kernel
priority : 0
type : digest
blocksize : 64
digestsize : 20

Major and Minor numbers

2009-01-30T23:43:00.000-08:00

Linux kernel treats all devices as file; they can be opened, closed, read and written using the same standard system calls. For every kind of Block and Character Devices, system creates the device files using mknod command and they define the device as major and minor number.

?? what... major and minor number....

Don't worry, I am going to tell about major and minor number... ;-)

To access any device, Operating System must be told what to do. All the routines for the specific device is jointly referred as Device Driver.

All devices controlled by the same device driver have common MAJOR number. MINOR number is used to identify the different devices and their controllers.

In another language, it can be said that: MAJOR number tells what kind of device it is and MINOR number tells about the characterstics/location of the device.

http://www.linux-tutorial.info/modules.php?name=MContent&pageid=94

Concept on SAN and Switches

2009-01-04T14:02:00.000-08:00

In above block diagram of SAN system, we can see mulitple servers : AIX, HP, LINUX and may be SUN, WINDOWS etc connected to storage like EMC, SAN, HITACHI (HDS) through Fibre Channel.

In between Servers and Storage, we can see Switches also called as Fabric. This switch allows the soft zoning in between the servers and storage avoiding direct connection between Servers and Storage.

(SOFT ZONING: It is the logical connection rather than hard connection between the servers and storage )

In switch, we can activate and deactivate the created the zone in between Servers and Storage.

Wait!!! I am missing something..
To create the zoning in between the Server and the Storage, you must have WWPN (World Wide Port Name) of either ends.

FYI there is a GUI software called as EFCM for SAN managementt.

==============================================================
Another thing to notice in above block diagram is that, each server goes to storage via two switches. Why should we use multi path?
Simple answer: For redundancy and multi path allows 2X speed of the data transfer.

Now the next question arises: What controls the multipath?
It's the multi-pathing software installed in the Servers. There are various types of mulitpating softwares. Basically there is MPIO (Multi Path I/O) which is default installed in AIX server.
There is another software: SDD (Subsystem Device Driver) that also controls multipath.
It really depends upon your choice to use either MPIO or SDD.

Multipath can also be considered as the technique employed for Load Balancing.

=============================================================

You know there are many questions in my mind.. ;-)
Now how does the Server recognize the different vendors Storage devices?

It's real easy answer.... It's again the software/filesets.. It's like a device driver which we call Host Attachment Software/Package.

Now the bottom line concept for the SAN system to work, there are three softwares running in the servers: OS, Multipathing software and Host Attachment Software.

================================================================

Are you interested in Switch Trunking? If yes, you can go through it, ok.. Otherwise skip it.. :-)

In above block diagram it says ISL (Inter Switch Link). If the two switches are connected via ISL then this is called as Trunking. And both of the switches behave as a single switch. This increases number of possible switching. This also helps in load balancing.

(FYI: If the ports connected by ISL, the port is called as E Port. Similarly if connected by Fiber, the port is called as F Port. If nothing connected , the port is called G Port)

There can be more trunking lines in between two switches for efficient load balancing and efficient switching.

In SAN system, Domain ID represents Switch. Usually you will find the following notation:
97(1) which implies Switch 1 Port 97

Go and find about QLogic and Emulex...

Hey by the way, I am trying to share only my knowledge. Don't rely 100% in it.. bcoz technology is ever changing. I am trying to update my every postings.

WWPN (World Wide Port Name)

2009-01-03T23:23:00.001-08:00

(WorldWide Port Name) The unique serial number burned into Fibre Channel adapters that identifies that network port from all others. The WWPN is the Fibre Channel counterpart of the MAC address in Ethernet adapters.

For the pretty clear concept of FIBRE CHANNEL go to :

http://www.pcmag.com/encyclopedia_term/0,2542,t=Fibre+Channel&i=43129,00.asp

IBM server series

2009-01-03T23:03:00.000-08:00

P series: POWER series (Performance Enhanced With Enhanced RISC)
To run AIX server

i series: To run ios
Power Systems including AS/400, iSeries, and System i

Z series: Mainframe computers (developed only by IBM)

http://www-03.ibm.com/systems/z/hardware/index.html

DS series: for data storage

X series: x86 architectures INTEL processors;
x86 servers for Windows and Linux
e.g for HMC (Hardware Management Console) server

How do I install the Administration web app in TOMCAT?

2008-12-28T22:21:00.000-08:00

If you install Tomcat 5.5 binaries, the Administration web app is not bundled with it; this describes how to add the Administration web app to your Tomcat 5.5 installation. (Tomcat 4.1 comes with the Administration web app as part of the binary).

The following refers to a Tomcat 5.5 set up on Windows 2000, so your path names will be different on *nix platforms. In this example, Tomcat 5.5.17 in installed in c:\Program Files\Apache Software Foundation\Tomcat 5.5 (this is my CATALINA_HOME).

Unzip or untar (be careful to use GNU tar) the file containing the administration web app files (eg. apache-tomcat-5.5.17-admin.zip) to a temporary directory, eg. c:\temp.
Copy c:\temp\apache-tomcat-5.5.17\conf\Catalina\localhost\admin.xml to the directory c:\Program Files\Apache Software Foundation\Tomcat 5.5\conf\Catalina\localhost.
Copy the entire directory tree c:\temp\apache-tomcat-5.5.17\server\webapps\admin

to the directory c:\Program Files\Apache Software Foundation\Tomcat 5.5\server\webapps. This is an overlay, so \server\webapps is just pointing you to the \server\webapps, and the admin directory with its contents will be the only thing you see added there.

Add a line to your c:\Program Files\Apache Software Foundation\Tomcat 5.5\conf\tomcat-users.xml file so that you have a user who has admin role. For example, add this line just before the last line (containing ) of the file:
Restart Tomcat.
Now when you visit http://localhost:8080/admin you should see a page that asks for a user name and password. If you still see the "no longer loaded" error message in your browser, you must either force a full reload of the web page (in Firefox, hold down Shift key while clicking on the Reload button) or just restart your browser completely.

http://wiki.apache.org/tomcat/HowTo#head-f50555909547d981d0e2b030323632b26047013e

Storage System

2008-11-13T10:10:00.000-08:00

Physical Volume: Name for an actual disk e.g SSA, SCSI disk; a PV can belong to a VG only

Volume Group: It is the largest unit of storage allocation; It contains multiple PV under a single VG name. The combined storage of all the PV makes a total space of VG which is used in turn by File Systems and Logical Volumes. A VG is splitted into PP; the size of PP within VG remains constant.

Why to create separate VG? e.g datavg and rootvg.
ans: To separate userdata from OS files; Disaster Recovery; Data portability; Data integrity and security | Maintenance is easy because you can update or reinstall OS without restoring data.
You can make VG unavailable using VARRYOFFVG.
There can be 255 VGs per System.

Physical Partition: PP is the division of PV. It is the basic unit of disk space allocation.
Default max no. of PP per PV is 1016. PP size cannot be changes dynamically but the number of PP per PV can be changed dynamically in mulitples of 1016. (i.e 1016, 2032, ...)

(Note: If you increase the more than 1016 PP per PV, then no. of PV per VG will be reduced)

Logical Volume: LV contains one or more LP within the VG. LV may span the PV if the multiple PV within the VG. LV size may be increased dynamically using SMIT even when users are working on that LV. However, the size cannot be reduced easily.

MAX PV=32 (128 BIG VG)
MAX LV=255 (512 BIG VG)
MAX VG =255 per system

Logical Partition: LP within a VG is the same size as PP

LVM does mapping between LV (logical view of storage) and PV (actual view of storage).

Why LVM?

2008-11-13T09:59:00.000-08:00

In traditional Storage System, there were many limitation:

1. Requirement of Contiguous Disk Space
2. Max partition size=Max Disk size (i.e Partition size cannot span multiple disks)
Thus no file system can be larger than Disk size
3. Pre-plan the partition size requirement, as after creation of partition, the partition cannot be resized.

To tackle with these problems, LVM (Logical Volume Manager) was developed.

Benefits of LVM:

1. LV solves the non-contiguous disk space requirement
2. LV can span to mulitiple disks
3. Dynamically increase LV size
4. LV can be mirrored
5. Harddisk easily added to the system.
6. LV can be relocated.

SAN storage

2008-11-11T12:17:00.000-08:00

SAN (Storage Area Network):

Why SAN?

How many drives your standalone PC can have?
ans: 2-3

Is that enough for the organization?
ans: of course not

If you lose your drive, what happens?
ans: total disaster, u lose all your data

=================================
ok then, SAN has all the solution...
Make Storage section consisting huge array of drives and allocate LUNs (Logical Unit Number) to the clients as per they demand.
Like One of my client need 2 GB for rootvg of AIX server. Then I allocate 1 LUN of 2 GB and give to the client.

Following is the connection configuration in SAN:

[100s of clients]-----HIGH SPEED FIBRE CHANNEL----[Tera byte storage]

Clients get access to their LUN via Fibre Channel and thus can be said that they are physically connected.

================================

For Redundancy RAID is implemented

RAID 0 --- striping (for high performance)
RAID 1 --- mirroring (for safe side operation i.e even a single drive fails, u still have another as backup)
RAID 5 --- parity bit enabled (data recovery even if one disk failed)

===================================================================
What about NAS?
NAS is similar thing, but it uses Ethernet instead of Fibre Channel. So NAS is slower than SAN.

Following is the connection configurtion in NAS

[CLIENTS]------ETHERNET---------[SERVER]------------[STORAGE]

==================================================================

Linux boots in 2.97 seconds

2008-11-11T09:32:00.000-08:00

Eat your heart out, Microsoft

By Egan Orion: Tuesday, 11 November 2008, 12:28 PM

SOFTWARE ENGINEERS at Japan's embedded Linux software vendor Lineo announced technology last week that can boot a low-power computer system within 2.97 seconds, the company claims.

Lineo calls its quick-start software system Warp 2, apparently either never having heard of IBM's ill-fated and abandoned OS/2 Warp operating system or not being particularly superstitious.

The company says Warp 2 consists of a bootloader, a customised Linux software stack, and a 'hibernation driver' similar to familiar suspend-to-disk software. Lineo's innovation is that its hibernation driver writes a snapshot of RAM into flash memory instead of to a hard disk.

The Warp 2 implementation is reportedly able to save multiple alternative system snapshots to enable rebooting either into a clean startup environment or to a previously saved session.

The hibernation driver is also capable of compressing the saved RAM image by about 50 per cent, depending upon what it contains. One of its demonstration tests reduced a 32MB RAM image to 19MB, Lineo claims.

In benchmark tests using an ARM CPU, a small low-power system running Warp 2 – with Linux, an X display subsystem, the tiny window manager twm and three xterm command line shells – booted an uncompressed 18.3MB RAM image in 2.97 seconds. Reportedly the system booted the same test suite from a compressed 6.8MB RAM image in 3.17 seconds.

Nearly instant-on Linux based systems are becoming common throughout the PC industry.

ASUS announced last May that it had begun preloading a BIOS flash embedded Linux and web browser system, called Express Gate, with all of the computer motherboards it ships.

That technology is based on DeviceVM Splashtop, which HP and Lenovo are reportedly also adopting. Dell Latitude On is a Montavista Linux system that runs on a separate ARM CPU. Not to be outdone, Toshiba and Intervideo have Linux based quick-boot systems too.

Moreover, the best-selling segment of the PC market now is netbooks – lightweight, small notebook style PCs that can handle light web browsing, email, photos and even streaming audio and video, practically as well as larger laptop and desktop PCs. Reportedly up to 25 per cent of netbooks run Linux, and Linux based fast-boot technology is ideally suited for the way people use those systems.

After all, no one needs to lug around a bulky laptop loaded down with heavyweight legacy software just to wibble the web, manage their email and photos, use their work-related, cloud-based software applications, and keep up with their social not-working addictions.

Less than two weeks ago Jim Zemlin, the executive director of the Linux Foundation, took note of all these developments and predicted that Linux will outship Windows next year.

That's not only possible but likely, we think, given that it looks like Linux will be shipping on a lot of PCs that are also loaded with Windows, and considering the better reliability and security, ease of use, and lower costs of Linux based systems, especially on netbooks.

The giant Vole of Redmond seems to be turning into an aging, slow dinosaur, surrounded by a quickly growing population of faster, smaller, and more agile little Linux mammals. µ