OSPF6D(8)               OpenBSD System Manager's Manual              OSPF6D(8)

NAME
     ospf6d - Open Shortest Path First daemon

SYNOPSIS
     ospf6d [-dnv] [-D macro=value] [-f file]

DESCRIPTION
     ospf6d is an Open Shortest Path First (OSPF) daemon which manages routing
     tables.  This implementation supports OSPF version 3, thus it is only ca-
     pable of maintaining IPv6 routing tables.

     OSPF is an interior gateway protocol designed to supersede RIP.  It has
     several advantages over RIP.  For instance, every router has an under-
     standing of the complete network topology.  Response to changes in the
     network is faster.  Furthermore, failure detection is improved.

     The OSPF daemon maintains a Link State Database (LSDB) containing infor-
     mation about routers and networks within an Autonomous System (AS).

     Dijkstra's shortest path first algorithm is used to compute a Routing In-
     formation Base (RIB) using the LSDB as input.  The Forwarding Information
     Base (FIB), a.k.a. the kernel routing table, is updated with information
     from the RIB.

     OSPF routers discover one another automatically via OSPF hello packets.
     OSPF routers communicate via two multicast groups: ff02::5 (all Shortest
     Path First routers) and ff02::6 (all Designated Routers).  OSPF runs di-
     rectly on top of IP and uses neither TCP nor UDP.  IP protocol number 89
     is reserved for OSPF.

     All routers in an OSPF network spend most of their time keeping each oth-
     ers' LSDBs in sync.  All routers must have the same information in the
     LSDB at all times.  Every time the LSDB is updated the RIB is updated; if
     needed the FIB is also updated.

     In a multi-access network such as Ethernet, it is unfeasible for all
     routers to synchronize their LSDB with all other routers in the network.
     In such networks a Designated Router (DR) and a Backup Designated Router
     (BDR) are elected.  The DR's responsibility is to synchronize with all
     routers; the BDR will not do much until the DR fails.  The first router
     in a network is automatically elected DR, the second router BDR.  All
     routers have a FULL adjacency with the DR and the BDR.  Routers with FULL
     adjacency exchange information about their LSDBs.  A router not elected
     either DR or BDR will have 2-WAY adjacency with all routers but the DR
     and BDR.  Routers with 2-WAY adjacency recognize that they know each oth-
     er, but do not exchange information about their LSDBs.  If a DR or BDR
     fails another router is elected DR or BDR and all routers form FULL adja-
     cencies with the newly elected DR or BDR.

     When routers are connected via point-to-point links, DR and BDR election
     is skipped since only two routers are connected to the link.

     To limit the impact changes in the network have on the LSDB it is possi-
     ble to segment an OSPF network into areas.  Area 0.0.0.0 (a.k.a. the
     backbone area) must always be present.  Routers can be configured as Area
     Border Router (ABR), being part of multiple areas.  Every area must have
     direct access to the backbone area.  ABRs not directly connected to the
     backbone area need to establish a virtual link to a router in the back-
     bone area.

     AS Border Routers (ASBR) are connected to an OSPF network and other ex-
     ternal networks via BGP, RIP, or static routing, and provide connectivity
     to networks outside the AS.

     ospf6d is usually started at boot time, and can be enabled by setting the
     following in /etc/rc.conf.local:

           ospf6d_flags=""

     See rc(8) and rc.conf(8) for more information on the boot process and en-
     abling daemons.

     A running ospf6d can be controlled with the ospf6ctl(8) utility.

     The options are as follows:

     -D macro=value
             Define macro to be set to value on the command line.  Overrides
             the definition of macro in the configuration file.

     -d      Do not daemonize.  If this option is specified, ospf6d will run
             in the foreground and log to stderr.

     -f file
             Specify an alternative configuration file.

     -n      Configtest mode.  Only check the configuration file for validity.

     -v      Produce more verbose output.

FILES
     /etc/ospf6d.conf        Default ospf6d configuration file.
     /var/run/ospf6d.sock    UNIX-domain socket used for communication with
                             ospf6ctl(8).

SEE ALSO
     ipsec.conf(5), ospf6d.conf(5), ospf6ctl(8)

     OSPF for IPv6, RFC 5340, July 2008.

     Authentication/Confidentiality for OSPFv3, RFC 4552, June 2006.

HISTORY
     The ospf6d program first appeared in OpenBSD 4.2.

BUGS
     Virtual links are currently not available in ospf6d.

     Support for multiple areas is currently not available in ospf6d.

     Unlike OSPF for IPv4, OSPF for IPv6 has no built-in support for authenti-
     cation of OSPF packets.  Instead, it relies on IPsec for packet authenti-
     cation.  Because OSPF uses multicast, IKE cannot be used for configuring
     IPsec flows securing OSPF traffic.  ospf6d is currently entirely unaware
     of IPsec and has no support for helping users setting up IPsec flows be-
     tween OSPF routers.  However, setting up IPsec flows between routers us-
     ing manual keying is strongly recommended to protect the OSPF network
     against spoofing attacks.  Note in particular that flows need to be con-
     figured for multicast groups ff02::5 and ff02::6.  See ipsec.conf(5).

OpenBSD 4.7                      March 6, 2010                               2
