.TH OPENNHRP 8 "16 November 2007" "" "OpenNHRP Documentation"

.SH NAME
opennhrp \- daemon to resolve next hop address in NBMA network

.SH SYNOPSIS
.BI "opennhrp [" "option" "]..."

.SH DESCRIPTION
.B opennhrp
implements the Next Hop Resolution Protocol (NHRP) which is used to
improve the efficiency of routing computer network traffic over
Non-Broadcast, Multiple Access (NBMA) Networks.
.PP
NHRP provides an ARP-like solution that allows a system to dynamically
learn the NBMA address of the other systems that are part of that network,
allowing these systems to directly communicate without requiring traffic
to use an intermediate hop.
.PP
.B opennhrp
implementation is based on RFC2332, but contains some modifications and
extensions to be compatible with Cisco NHRP/DMVPN implementation.
Modifications have been made for authentication extension, Cisco NAT
address extension and shortcut switching enhancements support.

.SH OPTIONS
The following options are recognized:

.IP "\fB\-a \fIadmin\-socket"
Specify management interface socket as
.IR admin\-socket .
The default is
.IR /var/run/opennhrp.socket .

.IP "\fB\-c \fIconfig\-file"
Use
.I config\-file
instead of
.I /etc/opennhrp/opennhrp.conf
for configuration.

.IP "\fB\-s \fIscript\-file"
Execute
.I script\-file
instead of
.I /etc/opennhrp/opennhrp\-script
on important events.

.IP "\fB\-p \fIpid\-file"
Store process id in
.I pid\-file
instead of
.IR /var/run/opennhrp.pid .
This file is also used to detect if opennhrp daemon is already running.
Pid-file is not created unless
.B -d
is specified too.

.IP "\fB-d"
Run in daemon mode, forking to background after initialization.

.IP "\fB-v"
Verbose. Print more log messages.

.IP "\fB-V"
Print version and exit.

.SH SIGNALS
.IP \fBSIGHUP
Forget all cached information about other system addresses.
.IP \fBSIGUSR1
Dump NHRP peer database to system log.

.SH FILES
.I /etc/opennhrp/opennhrp.conf
.RS
The system wide configuration file. See
.BR opennhrp.conf (5)
for further details.
.RE

.I /etc/opennhrp/opennhrp\-script
.RS
Script executed by
.B opennhrp
on important events. See
.BR opennhrp\-script (8)
for more information how the script is executed.
.RE

.I /var/run/opennhrp.socket
.RS
.BR opennhrp "(8) control socket"
.RE

.SH BUGS
Currently only IPv4 over IPv4 networks using NBMA GRE tunnels is
supported (you need Linux kernel 2.6.24-rc2 or later).
.PP
Replying with cached information to non-authorative resolution
requests is not implemented.
.PP
Please send bug reports to OpenNHRP issue tracker in SourceForge.

.SH "SEE ALSO"
.BR opennhrp.conf (5),
.BR opennhrpctl (8),
.BR opennhrp\-script (8)
.br
http://sourceforge.net/projects/opennhrp
.PP
For more information about the protocol see:
.br
RFC2332 NBMA Next Hop Resolution Protocol (NHRP)
.br
RFC2333 NHRP Protocol Applicability Statement

.SH AUTHORS
Timo Teras <timo.teras@iki.fi>