Here are the four fields you have to fill for each RARP entry:
You can comment out a record using this checkbox. Many RARP clients assume that if your server answers a RARP query, it can provide more boot services for this client. Diskless Linux workstation works this way. If your server does not provide such a service at one point in time, you are better off disabling the entry.
Note that several servers may process RARP queries on the same network without problems.
Enter a host name that is either defined in /etc/hosts (see the
menu "information about other hosts" in the Networking sub-menu
of Linuxconf) or in a DNS.
Or just enter a plain IP number (x.y.z.w).
The MAC address is a six-field hexadecimal number generally presented like this:
00:11:22:33:44:55
You can obtain this number different ways. Here are some:
Linux displays its MAC number when it boots. You can simply boot a configuration-less Linux computer and watch it print its MAC number to the screen. You will have plenty of time to write it down, since it won't boot much further than that, until a RARP server responds to its query.
Examples: diskless NFS-rooted Linux workstations and X terminals come to mind as configurationless Linux devices using (optionally) RARP to identify themselves.
Most Ethernet devices (all?) come with a DOS program allowing one to configure the device. This program prints the MAC number.
The Linux utility tcpdump can spy on the network and report on any packets going by. Tcpdump is quite handy for getting those "annoying to type" MAC numbers. Just execute:
tcpdump rarp
Boot the device and watch it there. Cut and paste the number into Linuxconf's dialog, add a name or an IP number and let Linuxconf activate the configuration. Watch the device complete its boot process successfully.
Automating this mechanism is on the TO-DO list for Linuxconf.
Put whatever you want here. Maybe just a reminder for why you disabled the entry.