1.\" $OpenBSD: dvmrpd.8,v 1.5 2008/04/28 07:46:41 jmc Exp $ 2.\" 3.\" Copyright (c) 2004, 2005, 2006 Esben Norby <norby@openbsd.org> 4.\" 5.\" Permission to use, copy, modify, and distribute this software for any 6.\" purpose with or without fee is hereby granted, provided that the above 7.\" copyright notice and this permission notice appear in all copies. 8.\" 9.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 10.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 11.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 12.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 13.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 14.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 15.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 16.\" 17.Dd $Mdocdate: April 28 2008 $ 18.Dt DVMRPD 8 19.Os 20.Sh NAME 21.Nm dvmrpd 22.Nd "Distance Vector Multicast Routing Protocol daemon" 23.Sh SYNOPSIS 24.Nm 25.Op Fl dnv 26.Op Fl f Ar file 27.Sh DESCRIPTION 28.Nm 29is the Distance Vector Multicast Routing Protocol 30.Pq DVMRP 31daemon, which manages multicast routing tables. 32This implementation supports DVMRP version 3.255, 33thus it is only capable of maintaining IPv4 multicast routing tables. 34.Pp 35DVMRP uses a distance vector routing algorithm to build 36reverse path multicast delivery trees. 37A flood and prune approach is used to determine which branches in 38the network have multicast listeners. 39The usual drawbacks of a distance vector route protocol applies to DVMRP: 40slow convergence and scalability issues. 41.Pp 42DVMRP routers communicate via the multicast group 224.0.0.4 43All DVMRP Routers. 44IP protocol number 2 45.Pq IGMP 46is used, furthermore DVMRP packets omit the use of TCP and UDP. 47.Pp 48It is possible to interconnect multicast networks with the use of tunnels. 49Tunnels can traverse routers and networks not supporting multicast. 50.Nm 51does not support tunneling as described in RFC 1075, 52since it has been abandoned. 53.Nm 54can tunnel multicast traffic using generic solutions such as 55.Xr gre 4 . 56.Pp 57DVMRP is used for handling multicast routing exclusively. 58It is not required that a unicast routing protocol is used in 59conjunction with DVMRP. 60.Pp 61.Nm 62is usually started at boot time, and can be enabled by 63setting the following in 64.Pa /etc/rc.conf.local : 65.Pp 66.Dl dvmrpd_flags=\&"\&" 67.Pp 68See 69.Xr rc 8 70and 71.Xr rc.conf 8 72for more information on the boot process 73and enabling daemons. 74.Pp 75A running 76.Nm 77can be controlled with the 78.Xr dvmrpctl 8 79utility. 80.Pp 81The options are as follows: 82.Bl -tag -width Ds 83.It Fl d 84Do not daemonize. 85If this option is specified, 86.Nm 87will run in the foreground and log to 88.Em stderr . 89.It Fl f Ar file 90Specify an alternative configuration file. 91.It Fl n 92Configtest mode. 93Only check the configuration file for validity. 94.It Fl v 95Produce more verbose output. 96.El 97.Sh FILES 98.Bl -tag -width "/var/run/dvmrpd.sockXX" -compact 99.It /etc/dvmrpd.conf 100Default 101.Nm 102configuration file. 103.It /var/run/dvmrpd.sock 104Unix-domain socket used for communication with 105.Xr dvmrpctl 8 . 106.El 107.Sh SEE ALSO 108.Xr dvmrpd.conf 5 , 109.Xr dvmrpctl 8 110.Rs 111.%R "draft-ietf-idmr-dvmrp-v3-11" 112.%T "DVMRP Version 3" 113.%D August 2000 114.Re 115.Sh HISTORY 116The 117.Nm 118program first appeared in 119.Ox 4.0 . 120