Novell LINUX ENTERPRISE SERVER 10 SP2 - INSTALLATION AND ADMINISTRATION Installation Manual page 610

means of the script modify_resolvconf. If the file /etc/resolv.conf has
been temporarily modified by this script, it contains a predefined comment giving in-
formation about the service that modified it, the location where the original file has
been backed up, and how to turn off the automatic modification mechanism. If /etc/
resolv.conf is modified several times, the file includes modifications in a nested
form. These can be reverted in a clean way even if this reversal takes place in an order
different from the order in which modifications were introduced. Services that may
need this flexibility include isdn, pcmcia, and hotplug.
If a service was not terminated in a normal, clean way, modify_resolvconf can
be used to restore the original file. Also, on system boot, a check is performed to see
whether there is an uncleaned, modified resolv.conf, for example, after a system
crash, in which case the original (unmodified) resolv.conf is restored.
YaST uses the command modify_resolvconf check to find out whether resolv
.conf has been modified and subsequently warns the user that changes will be lost
after restoring the file. Apart from this, YaST does not rely on modify_resolvconf,
which means that the impact of changing resolv.conf through YaST is the same
as that of any manual change. In both cases, changes have a permanent effect. Modifi-
cations requested by the mentioned services are only temporary.
/etc/hosts
In this file, shown in Example 30.6, "/etc/hosts" (page 592), IP addresses are as-
signed to hostnames. If no name server is implemented, all hosts to which an IP connec-
tion will be set up must be listed here. For each host, enter a line consisting of the IP
address, the fully qualified hostname, and the hostname into the file. The IP address
must be at the beginning of the line and the entries separated by blanks and tabs.
Comments are always preceded by the # sign.
Example 30.6 /etc/hosts
127.0.0.1 localhost
192.168.0.20 sun.example.com sun
192.168.0.1 earth.example.com earth
592 Installation and Administration