I recently had to install CentOS 4.4 on the Asus P5GC-MX motherboard. The board works very well with the installer as long as you aren’t doing a network install as the network drivers are not available.
Here is some information about the boards network controller, that was almost impossible to track down. The board uses a network chipset called the Attansic L2.
More specifically, you can compile the drivers from source files against the current kernel.
I have included a copy of the driver for you to download if you need it. I searched through many mailing list postings to locate these file and I can confirm that it will compile against the kernel in CentOS 4.4.
In order to compile the kernel module you will need to install the kernel source for your current kernel version (yum install kernel-devel and kernel-smp-devel if you need it). You will also need to create a symbolic link from the source to /usr/src/linux as the kernel module looks at this location for the current kernel.
Then you need to cd to the src directory in the archive and run make to compile the module.
Once completed you can run insmod to install the module into the kernel.
After you have done that, you will need to make sure you create module alias between the module and eth0.
It is a little bit of a pain to get working, but it can be done.
Good luck and I hope that the source files come in handy to somebody out there.