nss-icmp(7) - Linux man page

Name

nss-icmp - A nameservice hostname module for ICMP

Description

The nss-icmp nameservice module provides reverse hostname lookup over ICMP. If installed in /etc/nsswitch.conf, it will act on programs calling gethostbyaddr(3) and related functions and attempt to request the specified host's fully qualified domain name over ICMP.

In order to do so, nss-icmp relies on the idnlookup(1) program being installed on the system. It also implements a cache, which will remember the remote host's response for as long as the TTL (Time-to-Live) value in the response specifies. It will also remember non-responsive hosts, so that time-outs will not have to happen twice.

The first time nss-icmp is called, it will read a configuration file, which by default will be named /etc/nss-icmp.conf (although this name can be changed during compilation). The configuration file specifies certain parameters to control how nss-icmp operates. Its file format is described in the nss-icmp.conf(5) man page.

Author

Fredrik Tolf <fredrik@dolda2000.com>

See Also

idnlookup(1), icmpdnd(8), nsswitch.conf(5), nss-icmp.conf(5), RFC 1788