ethers Database

The ethers database is built from information that is entered into the /etc/ethers file. This database associates host names to their Media Access Control (MAC) addresses. You need to create an ethers database only if you are running the RARP daemon. That is, you need to create this database if you are configuring network clients.

RARP uses the file to map MAC addresses to IP addresses. If you are running the RARP daemon in.rarpd, you need to set up the ethers file and maintain this file on all hosts that are running the daemon to reflect changes to the network.

The ethers(4) man page contains the complete syntax for this database. The basic syntax is shown here:

MAC-address   hostname   #comment

MAC-address

MAC address of the host

hostname

Official name of the host

#comment

Any note that you want to append to an entry in the file

The equipment manufacturer provides the MAC address. If a system does not display the MAC address during the system booting process, see your hardware manuals for assistance.

When adding entries to the ethers database, ensure that host names correspond to the primary names in the hosts not to the nicknames, as follows.

Example 9–7 Entries in the ethers Database

8:0:20:1:40:16  fayoum
8:0:20:1:40:15  nubian 
8:0:20:1:40:7   sahara    # This is a comment
8:0:20:1:40:14  tenere