!! OSPF, Open Shortest Path First



** [#ospf__open_shortest_path_first OSPF, Open Shortest Path First]

** [#salient_features Salient features]

** [#some_links_ Some links:]

** [#local_help_pages_ Local help pages:]

** [#books_ Books:]



This is a link state protocol. There are various versions



* OSPF (Version 2), (http://www.ietf.org/rfc/rfc2328.txt RFC 2328) ((http://www.zvon.org/tmRFC/RFC2328/Output/ indexed html))

* OSPF for IPv6 (Version 3), (http://www.ietf.org/rfc/rfc2740.txt RFC 2740) ((http://www.zvon.org/tmRFC/RFC2740/Output/ indexed html))





!! Salient features

* OSPF can discover neighbors through multicast "hello" packets. This feature can be crucial in allowing new nodes to be added to the mesh without requiring configuration changes to pre-existing nodes.

* OSPF supports a mode called '[p2mp point-to-multipoint]' where [Router routers] on a network (to use the RFC term for a [Subnet subnet]) do not all necessarily have to be able to communicate directly with one-another (See sections 2.1.1 and 12.4.1.4 of the RFC). This is important to support [802.11] running in [IBSS] mode as described in Layer2Assumptions

* Link state information is restricted to an area, area 0 being special, namely the [BackBone]. Communications between areas must transit the backbone. The backbone must be contiguous or 'patched up' with virtual links.



!! Some links:

* (http://www.zebra.org - Free routing software that supports OSPF) (RFC 2328)

* (http://www.cisco.com/warp/public/104/1.html - OSPF design guide on Cisco's site)

* (http://felinemenace.org/~andrewg/ - Andrew Griffiths site)



!! Local help pages:

* [Router]

* [Routing]

* [OSPFwindows OSPF for windowsXP]

* [Zebra Zebra and Quagga]



!! Books:



* Cisco Router OSPF : design and implementation guide, William Parkhurst 1998, !McGraw-Hill. ISBN:0-07-048626-3