nss-myhostname — Provide host name resolution for the locally configured system hostname.
nss-myhostname is a plugin for the GNU Name Service Switch
(NSS) functionality of the GNU C Library (glibc)
providing host name resolution for the locally configured system
hostname as returned by
Various software relies on an always resolvable local host name. When
using dynamic hostnames this is usually achieved by patching
/etc/hosts at the same time as changing the host
name. This however is not ideal since it requires a writable
/etc file system and is fragile because the file
might be edited by the administrator at the same time. nss-myhostname
simply returns all locally configure public IP addresses, or -- if none
are configured -- the IPv4 address 127.0.0.2 (which is on the local
loopback) and the IPv6 address ::1 (which is the local host) for
whatever system hostname is configured locally. Patching
/etc/hosts is thus no longer necessary.
To activate the NSS modules,
has to be added to the line starting with "
It is recommended to put
last in the
nsswitch.conf line to make
sure that this mapping is only used as fallback, and any DNS
/etc/hosts based mapping takes precedence.
# /etc/nsswitch.conf passwd: compat group: compat shadow: compat hosts: files dns
myhostnamenetworks: files protocols: db files services: db files ethers: db files rpc: db files netgroup: nis
To test, use glibc's getent tool:
$ getent ahosts `hostname` ::1 STREAM omega ::1 DGRAM ::1 RAW 127.0.0.2 STREAM 127.0.0.2 DGRAM 127.0.0.2 RAW
In this case the local host name is