Setting up a Second Network Card and Completing Network Configuration
by David Johns and Jonathan Arehart

When demonstrating the use of Lynx earlier, the documentation specified a specific file to move into the appropriate directory. This file (dmfe.o) was a binary kernel module for the second ethernet card that comes on these computers. This document is about configuring that second ethernet card.

Configuring the second Ethernet card

Once again as root, run Linuxconf. Go to the section Config, Networking, Client tasks, Basic host information and press -enter- (it is the fourth line in the main Linuxconf menu).

When you first enter this specific screen, there will be information for your first ethernet card (the one you configured during the installation) under the heading "Adaptor 1". It should have the address information as well as the machine name and network (domain) name you set during the install. The address and names you put here are for the TxIS network, so you will want to use different values when you install your own Linux machine.

For now, use the down arrow to reach the heading "Adaptor 2" and configure it as below:

			--------Adaptor 2--------
			[X] Enabled
Config mode		(o) Manual ( ) Dhcp ( ) Bootp		
Primary name + domain
Aliases (opt)
IP address		192.168.1.x
Netmask	(opt)
Net device		eth1
Kernel module		dmfe
I/O port (opt)
Irq (opt)
When you set up your own Linux system, you will probably want to set the IP address of your second adapter to However, during class you will want this address to be unique, since each of the machines is physically connected to the two networks in the room. You can leave the name, domain, and alias information blank, and Linuxconf will use the values from adapter 1.
-Tab- to the Accept button and press -return- to save your changes.

Configuring DNS

Go to Config, Networking, Client tasks, Name server specification (DNS) and press -enter- (this is the fifth line in the main Linuxconf menu).

Set the options as follows:

DNS usage			[X] DNS is required for normal operation
default domain
nameserver 1
nameserver 2 (opt)
nameserver 3 (opt)
search domain 1 (opt)
search domain 2 (opt)
search domain 3 (opt)
"" should be set to during class and the "fake" domain you chose earlier on your own system. The name server is set to (localhost) so that your firewall will use itself as a name server. The name server software (named) will know where o go ask about addresses it doesn't know once we configure it (below).
-Tab- to the Accept button and press -return- to save your changes.

Enable Routing

Go to Config, Networking, Client tasks, Routing and gateways, Defaults (the seventh line in Linuxconf).

Set the options as follows:

Default gateway
			[X] enable routing
(Note: You will want to set this to your ISP's default gateway after you install Linux. If you don't your network traffic will go nowhere! If you are using DHCP to determine your external IP address, you should leave this blank, as DHCP will fill it in for you. RoadRunner and ADSL usually use DHCP.)
-Tab- to the Accept button and press -return- to save your changes.

Setting up DNS forwarding

Go to Config, Networking, Server tasks, Domain Name Server (DNS), Config, forwarders and press -enter-.

Set the option as follows:

IP address
(Note: You should change this to your ISP's DNS server as soon as you know what it is! Failing to do so will result in extremely poor network performance! There are a few ISPs that don't like to give this information out if it isn't in an installer (or some similar form). It seems more common with ISPs that use DHCP. The upshot is that you may have to bug them a bit to get the information.)
-Tab- to the Accept button and press -return- to save your changes.

See Also: ifconfig, named, route
Related Pages: DNS HOWTO