Datasheet

“main” (Installation and Administration) — 2004/6/25 — 13:29 — page 434 — #460
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/etc/resolv.conf
The domain to which the host belongs is specified in this file (keyword
search). Also listed is the status of the name server address (keyword
nameserver) to access. Multiple domain names can be specified. When
resolving a name that is not fully qualified, an attempt is made to generate
one by attaching the individual search entries. Use multiple name servers
by entering several lines, each beginning with nameserver. Precede com-
ments with # signs.
Example 21.5: /etc/resolv.conf
# Our domain
search example.com
#
# We use sun (192.168.0.20) as nameserver
nameserver 192.168.0.20
An example of /etc/resolv.conf is shown in Example 21.5. YaST enters
the specified name server here. Some services, like pppd (wvdial), ipppd
(isdn), dhcp (dhcpcd and dhclient), pcmcia, and hotplug, modify the file
/etc/resolv.conf by 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 information 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 modifi-
cations 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 modifica-
tions were introduced. Services that may need this flexibility include isdn,
pcmcia, and hotplug.
If it happens that a service was not terminated in a normal, clean way,
modify_resolvconf can be used to restore the original file. Also, on sys-
tem boot, a check is performed to see whether there is an uncleaned, mod-
ified resolv.conf (e.g., 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 will subsequently warn the user that
changes will be lost after restoring the file. Apart from this, YaST will 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. Modifications requested by
the above-mentioned services are only temporary.
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21.3. Manual Network Configuration