On Apache/2.4.6 (CentOS)
Under GNU General Public License
2025-06-23 22:12 @127.0.0.1 CrawledBy Wget/1.21.2
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:
o 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).
o The hostname "localhost" is resolved to the IP addresses 127.0.0.1 and ::1.
o 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
::1 RAW
127.0.0.2 STREAM
127.0.0.2 DGRAM
127.0.0.2 RAW
In this case the local hostname is omega.
SEE ALSO
systemd(1), nss-mymachines(8), nsswitch.conf(5), getent(1)
systemd 219 NSS-MYHOSTNAME(8)
Generated by $Id: phpMan.php,v 4.55 2007/09/05 04:42:51 chedong Exp $ Author: Che Dong
On Apache/2.4.6 (CentOS)
Under GNU General Public License
2025-06-23 22:12 @127.0.0.1 CrawledBy Wget/1.21.2