Node: Name servers (DNS), Next: Monitoring important files, Previous: Network File System (NFS), Up: Key concepts
There are two ways to specify addresses on the internet (called IP
addresses). One is to use the textual address like ftp.uu.net
and the other is to use the numerical form 192.48.96.9
. Alas,
there is no one-to-one correspondence between the numerical addresses
and the textual ones, thus a service is required to map one to the
other.
The service is performed by one or more special hosts on the network
called nameservers. Each host must know how to contact a
nameserver or it will probably hang the first time you give it an IP
address. You tell it how to contact a nameserver by editing the
text-file /etc/resolv.conf
. This file must contain the domain
name for your domain and a list of possible nameservers which can be
contacted, in order of priority. Because this is a special file which
every host must have, you don't have to use the editing facilities in
cfengine explicitly. You can just define the nameservers for each host
in the cfengine file and cfengine will do the editing automatically. If
you want to change the priority of nameservers later, or even change the
list then a simple change of one or two lines in the configuration file
will enable you to reconfigure every host on your network automatically
without having to do any editing yourself!