Hi,
As far as I know, that driver is not in the 2.2 series kernels but is in the 2.4 series.
In principle you should be able to :
cp fa311.o /lib/modules/2.2.x/net/
edit /etc/modules.conf to all the line
alias eth0 fa311 (i.e., as shown in last posting above)
depmod -ae (updates module dependencies)
Then use 'netconf' (easiest for redhat) or yast2 / yast (Suse) to configure the 'eth0' interface with correct ip settings.
In theory eth0 should then be activated each reboot...
If that doesn't work, there is a version of the natsemi driver (as used by FA311) included in the 2.4 kernel source. In order to simplify the dependency issues why not just make the move to 2.4 and compile a new kernel. In fact, you may find that installing a pre-compiled 2.4 series kernel suits your need and, most probably, that would install a natsemi driver for you. You'd find it here :
/lib/modules/2.4.7/kernel/drivers/net/natsemi.o
(where 2.4.7 was your kernel version).
From there it should work with the insmod/modprobe commands or by specifying 'alias eth0 natsemi' in your /etc/modules.conf.
See also
Hope this is of some help
Rgds