nss-resolve, libnss_resolve.so.2 — Provide hostname resolution via
nss-resolve is a plug-in module for the GNU Name Service Switch (NSS) functionality of the GNU C Library (glibc) enabling it to resolve host names via the systemd-resolved(8) local network name resolution service. It replaces the nss-dns plug-in module that traditionally resolves hostnames via DNS.
To activate the NSS module, add "
resolve" to the line starting with
/etc/nsswitch.conf. Specifically, it is recommended to place
resolve" early in
hosts:" line (but
after the "
files" or "
mymachines" entries), right before the
dns" entry if it exists, followed by "
[!UNAVAIL=return]", to ensure DNS queries
are always routed via
systemd-resolved(8) if it is
running, but are routed to nss-dns if this service is not available.
Note that systemd-resolved will synthesize DNS resource
records in a few cases, for example for "
localhost" and the
current hostname, see
for the full list. This duplicates the functionality of
but it is still recommended (see examples below) to keep
nss-myhostname configured in
/etc/nsswitch.conf, to keep those names resolveable if
systemd-resolved is not running.
Here is an example
/etc/nsswitch.conf file that enables nss-resolve
passwd: compat mymachines systemd group: compat mymachines systemd shadow: compat hosts: files mymachines resolve [!UNAVAIL=return] dns myhostname networks: files protocols: db files services: db files ethers: db files rpc: db files netgroup: nis