Net Gains: Networking Adapters - page 6
Your Physical Connection to the Network
Either all else has failed or you really want to know what is going on underneath. Be prepared to use the man program to get the real details because we will not present them here. Remember, any changes made using this approach will not be easily changed using linuxconf. Keep track of every file you change and keep a backup so you can return to a working configuration. It is possible to use a combination of linuxconf and manual changes as are noted here, but try to avoid naming conflicts such as the use of eth1 if linuxconf uses eth0. Subsequent additions via linuxconf could then break things and debugging will be difficult at best.
There are two sets of things to deal with when you hit this level. The first is the script files that will start things up and the second is the applications you will use to get the job done. In this case, the script files can be found in /etc/rc.d.
Note, some Linux distributions use a different startup procedure that may use different script files or directories. Check out the Linux distribution documentation if you do not find the files and directories mentioned here.
The rc.sysinit script is where the network is configured. Manual changes will normally be added near the start of this file, because they must be done prior to starting network applications like a Web server.
Network configuration are accomplished using two programs: modprobe and ifconfig. Use the man program to check out the details of these programs. If you don't know or cannot figure out how to do this, then these kinds of changes should not be attempted.
The modprobe program is used to start up device drivers. The ifconfig program is used to configure IP settings. A typical sequence of commands is:
/sbin/modprobe ne.o io=0x310
/sbin/ifconfig eth0 10.0.0.1 netmask 255.255.255.0
Using the full path name for the programs is a good idea when adding lines to a script that you did not write yourself. This example configures an ISA NE2000 network adapter at I/O port 0x310 to use IP address 10.0.0.1.
If you get this much working then getting more adapters up and running the hard way should not be too difficult.
Mucking around with device driver modules is not much fun unless you configure Linux as a hobby. This article does not provide extensive coverage of the issues, but hopefully it has presented enough material to get the job done or point you in the right direction. Check out the EHTERNET-HOWTOs on various Linux sites (such as LinuxStart) for more details.