Wednesday, July 27, 2011

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

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 #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

# 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

>>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
# modprobe ieee80211_crypt_tkip

# 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.

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 (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.

Wednesday, July 6, 2011

Directories Terminology: Active Directory, eDirectory, Lotus Domino Directory

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 ''.

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

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

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