Most, if not all, network applications rely on you to set the local host's name to some reasonable value. This setting is usually made during the boot procedure by executing the hostname command. To set the hostname to name, enter:
# hostname name |
It is common practice to use the unqualified hostname without specifying the domain name. For instance, hosts at the Virtual Brewery (described in Appendix A) might be called vale.vbrew.com or vlager.vbrew.com. These are their official fully qualified domain names (FQDNs). Their local hostnames would be the first component of the name, such as vale. However, as the local hostname is frequently used to look up the host's IP address, you have to make sure that the resolver library is able to look up the host's IP address. This usually means that you have to enter the name in /etc/hosts.
Some people suggest using the domainname command to
set the kernel's idea of a domain name to the remaining part of the
FQDN. This way you could combine the output from
hostname and domainname to get
the FQDN again. However, this is at best only half
correct. domainname is generally used to set the
host's NIS domain, which may be entirely different from the DNS domain
to which your host belongs. Instead, to ensure that the short form of
your hostname is resolvable with all recent versions of the
hostname command, either add it as an entry in your
local Domain Name Server or place the fully qualified domain name in
the /etc/hosts file. You may then use the
--fqdn argument to the
hostname command, and it will print the fully
qualifed domain name.