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NSS-MYHOSTNAME(8)                                   nss-myhostname                                  NSS-MYHOSTNAME(8)



NAME
       nss-myhostname, libnss_myhostname.so.2 - Provide hostname resolution for the locally configured system
       hostname.

SYNOPSIS
       libnss_myhostname.so.2

DESCRIPTION
       nss-myhostname is a plugin for the GNU Name Service Switch (NSS) functionality of the GNU C Library (glibc)
       primarily providing hostname resolution for the locally configured system hostname as returned by
       gethostname(2). The precise hostnames resolved by this module are:

       ·   The local, configured hostname is resolved to all locally configured IP addresses ordered by their scope,
           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).

       ·   The hostname "localhost" is resolved to the IP addresses 127.0.0.1 and ::1.

       ·   The hostname "gateway" is resolved to all current default routing gateway addresses, ordered by their
           metric. This assigns a stable hostname to the current gateway, useful for referencing it independently of
           the current network configuration state.

       Various software relies on an always-resolvable local hostname. When using dynamic hostnames, this is
       traditionally achieved by patching /etc/hosts at the same time as changing the hostname. This is problematic
       since it requires a writable /etc file system and is fragile because the file might be edited by the
       administrator at the same time. With nss-myhostname enabled changing /etc/hosts is unncessary, and on many
       systems the file becomes entirely optional.

       To activate the NSS modules, "myhostname" has to be added to the line starting with "hosts:" in
       /etc/nsswitch.conf.

       It is recommended to place "myhostname" last in the nsswitch.conf line to make sure that this mapping is only
       used as fallback, and any DNS or /etc/hosts based mapping takes precedence.

EXAMPLE
       Here's an example /etc/nsswitch.conf file, that enables myhostname correctly:

           passwd:   compat
           group:    compat
           shadow:   compat

           hosts:    files dns mymachines myhostname
           networks:       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

systemd 219                                                                                         NSS-MYHOSTNAME(8)