After building oscar client image it was realized that there is no driver avaialbe by default in the RedHat 9 distro for gigabit Ethernet card so we downloaded source code for the intel gigabit driver from downloadfinder.intel.com and installed it on server as well as added this newly compiled driver in cluster client image.
Note: OS is RedHat 9 and Oscar 4.2 is the toolkit under discussion. Now they have lauched oscar 5.0 with so many options for customization.
Follwing are the steps taken
#tar -xvzf e1000.tar.gz
# cd src
# cp e1000.o /lib/moduels.2.4.20-8/kernel/driver/net and
# cp e1000.o /lib/moduels.2.4.20-8/kernel/driver/net/e1000/
# Reboot Machine or run kudzu
# configure the card i.e assign IP and proper netmask and you are done
Modifying the Client Image
# cp e1000.o /var/lib/systemimager/images/lib/modules/2.4.20-8smp/kernel/driver/net/e1000 and /net/e1000/
# Now Copy /etc/modules.conf to /var/lib/systemimager/images/oscarimage/etc