My system is Redhat9.I have successfully updated the kernel to 2.6.11.6.But now the iptables does not work in my new kernel. I modified my /etc/rc.d/rc.sysinit.
Change
if ! LC_ALL=C grep -iq nomodules /proc/cmdline 2>/dev/null && [ -f /proc/ksyms ]; then
USEMODULES=y
fi

to

if [ ${KVERSION} == "2.6" ]; then

if ! LC_ALL=C grep -iq nomodules /proc/cmdline 2>/dev/null && [ -f /proc/kallsyms ]; then
USEMODULES=y
fi

else

if ! LC_ALL=C grep -iq nomodules /proc/cmdline 2>/dev/null && [ -f /proc/ksyms ]; then
USEMODULES=y
fi

fi

And I reboot and find the iptables works fine.But there come a new problem.
I can't connect to net.Before I change the /etc/rc.d/rc.sysinit,I can connect to net.
And the redhat-config-netword tell me that :
redhat-config-network:
eth0 has an alias to module r8169 in modules.conf,
instead of currently loaded module eth1394!
And when i reboot or shutdown computer,I see a error"Device eth0 has different MAC than expected"

How can i solve these problems?Can anybody help me?
I am hopeless!

Do you have the correct module for your card inserted into the kernel? What does lsmod have to say? The 2.6 kernels use different module utilities, so hopefully you updated them too (I'm not sure of the consequences if you didn't -- things like modprobe and lsmod probably just wouldn't work).

btmiller,thank you for you reply.
If i don't modify the /etc/rc.d/rc.sysinit,lsmod's result contain the module r8169.But when after i modify the file,lsmod's result didn't contain the module r8169.
It seems that the kernel load the module eth1394 for the net card.
How can i get the kernel load the module r8169 for the net card when booting??

Nobody know the solution of the question?
How can i specify the net card load the module i want it to load?

Try doing it by hand:

modprobe r8169

then see if eth0 shows up in ifconfig. If not, compile the r8169 as a module (or just compile it into the kernel).