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.TH NSS-ICMP 7 "12 Jan 2006" "icmpdn @VERSION@" "ICMP Hostname Manual"
.SH NAME
nss-icmp - A nameservice hostname module for ICMP
.SH DESCRIPTION
The \fBnss-icmp\fP nameservice module provides reverse hostname lookup
over ICMP. If installed in \fB/etc/nsswitch.conf\fP, it will act on
programs calling \fBgethostbyaddr\fP(3) and related functions and
attempt to request the specified host's fully qualified domain name
over ICMP.
.P
In order to do so, \fBnss-icmp\fP relies on the \fBidnlookup\fP(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.
.P
The first time \fBnss-icmp\fP is called, it will read a configuration
file, which by default will be named \fB/etc/nss-icmp.conf\fP
(although this name can be changed during compilation). The
configuration file specifies certain parameters to control how
\fBnss-icmp\fP operates. Its file format is described in the
\fBnss-icmp.conf\fP(5) man page.
.SH AUTHOR
Fredrik Tolf <fredrik@dolda2000.com>
.SH SEE ALSO
\fBidnlookup\fP(1), \fBicmpdnd\fP(8), \fBnsswitch.conf\fP(5),
\fBnss-icmp.conf\fP(5), \fIRFC 1788\fP