1.\" $OpenBSD: ospfd.8,v 1.23 2009/04/07 14:57:33 reyk Exp $ 2.\" 3.\" Copyright (c) 2004, 2005, 2007 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 7 2009 $ 18.Dt OSPFD 8 19.Os 20.Sh NAME 21.Nm ospfd 22.Nd "Open Shortest Path First daemon" 23.Sh SYNOPSIS 24.Nm 25.Op Fl dnv 26.Oo Xo 27.Fl D Ar macro Ns = Ns Ar value Oc 28.Xc 29.Op Fl f Ar file 30.Op Fl s Ar socket 31.Sh DESCRIPTION 32.Nm 33is an Open Shortest Path First 34.Pq OSPF 35daemon which manages routing tables. 36This implementation supports OSPF version 2, thus it is only capable of 37maintaining IPv4 routing tables. 38.Pp 39OSPF is an interior gateway protocol designed to supersede RIP. 40The OSPF daemon maintains a Link State Database 41.Pq LSDB 42consisting of routers and networks. 43.Pp 44Dijkstra's shortest path first algorithm is used to compute the Route 45Information Base using the LSDB as input. 46The Forwarding Information Base a.k.a. the kernel route table is updated 47with information from the RIB. 48.Pp 49OSPF routers communicate via two multicast groups: 224.0.0.5 all Shortest 50Path First routers and 224.0.0.6 all Designated Routers. 51The IP protocol number 89 is reserved for OSPF, furthermore OSPF packets 52omit the use of TCP and UDP. 53.Pp 54OSPF has several advantages over RIP. 55For example every router has a complete network topology. 56Response to changes in the network are faster. 57Furthermore fail detection is much improved. 58.Pp 59All routers in an OSPF network spend most of their time keeping each others 60LSDBs in sync. 61All routers must have the same information in the LSDB at all times. 62Every time the LSDB is updated the RIB is updated; if needed the FIB is 63also updated. 64.Pp 65OSPF aware routers discover each other via OSPF hello packets. 66.Pp 67In a multiaccess network such as Ethernet it is unfeasible for all routers 68to synchronize with all other routers in the network. 69In such networks a Designated Router 70.Pq DR 71and a Backup Designated Router 72.Pq BDR 73is elected. 74The DR's responsibility is to synchronize with all routers; the BDR will 75not do much until the DR fails. 76The first router in a network is automatically elected DR, the second 77router BDR. 78All routers have a FULL adjacency with the DR and the BDR. 79A router not elected either DR or BDR will have 2-WAY adjacency with all 80routers but the DR and BDR. 81Routers that form 2-WAY adjacency recognize that they know each other. 82In case a DR or BDR should fail another router is elected and all routers 83change state on the newly elected router and synchronize to it. 84.Pp 85When routers are connected via point-to-point links, the DR and BDR 86election is skipped since only two routers are connected. 87.Pp 88To limit the impact changes in the network have on the LSDB it is possible 89to segment an OSPF network into areas. 90Area 0.0.0.0 a.k.a. the backbone area must always be present. 91Routers can be configured as Area Border Router 92.Pq ABR , 93being part of multiple areas. 94Every area must have direct access to the backbone area. 95ABRs not directly connected to the backbone area need to establish a 96virtual link to a router in the backbone area. 97Virtual links are currently not available in 98.Nm . 99.Pp 100AS Border Routers 101.Pq ASBR 102are connected to an OSPF network and other external networks, BGP, RIP, 103or statically routed. 104.Pp 105.Nm 106is usually started at boot time, and can be enabled by 107setting the following in 108.Pa /etc/rc.conf.local : 109.Pp 110.Dl ospfd_flags=\&"\&" 111.Pp 112See 113.Xr rc 8 114and 115.Xr rc.conf 8 116for more information on the boot process 117and enabling daemons. 118.Pp 119A running 120.Nm 121can be controlled with the 122.Xr ospfctl 8 123utility. 124.Pp 125The options are as follows: 126.Bl -tag -width Ds 127.It Fl D Ar macro Ns = Ns Ar value 128Define 129.Ar macro 130to be set to 131.Ar value 132on the command line. 133Overrides the definition of 134.Ar macro 135in the configuration file. 136.It Fl d 137Do not daemonize. 138If this option is specified, 139.Nm 140will run in the foreground and log to 141.Em stderr . 142.It Fl f Ar file 143Specify an alternative configuration file. 144.It Fl n 145Configtest mode. 146Only check the configuration file for validity. 147.It Fl s Ar socket 148Use an alternate location for the default control socket. 149.It Fl v 150Produce more verbose output. 151.El 152.Sh FILES 153.Bl -tag -width "/var/run/ospfd.sockXX" -compact 154.It /etc/ospfd.conf 155Default 156.Nm 157configuration file. 158.It /var/run/ospfd.sock 159Unix-domain socket used for communication with 160.Xr ospfctl 8 . 161.El 162.Sh SEE ALSO 163.Xr ospfd.conf 5 , 164.Xr ospfctl 8 165.Rs 166.%R RFC 2328 167.%T "OSPF Version 2" 168.%D April 1998 169.Re 170.Rs 171.%R RFC 3137 172.%T "OSPF Stub Router Advertisement" 173.%D June 2001 174.Re 175.Sh HISTORY 176The 177.Nm 178program first appeared in 179.Ox 3.7 . 180