Editing Open Shortest Path First (section)

{{Short description|Routing protocol for IP networks}}
{{Use mdy dates|date=September 2017}}
{{Use American English|date=May 2020}}

{{Infobox networking protocol
|       title = Open Shortest Path First
|     purpose = [[Routing protocol]]
|        date = {{Start date and age|1989}}
|        rfcs = {{IETF RFC|1131|1247|1583|2178|2328|3101|5709|6549|6845|6860|7474|8042|3137|3509|plainlink=yes}}...
}}

{{Infobox networking protocol
|title = OSPF for IPv6
|date = {{Start date and age|1999}}<!--Fill in: Year (4 digits), month and day (2 digits)-->
|rfcs = {{IETF RFC|2740|5340|6845|6860|7503|8362|plainlink=yes}}...
}}

'''Open Shortest Path First''' ('''OSPF''') is a [[routing protocol]] for [[Internet Protocol]] (IP) networks. It uses a [[link state routing]] (LSR) algorithm and falls into the group of [[interior gateway protocol]]s (IGPs), operating within a single [[Autonomous system (Internet)|autonomous system]] (AS).

OSPF gathers link state information from available routers and constructs a topology map of the network. The topology is presented as a routing table to the [[internet layer]] for routing packets by their destination [[IP address]]. OSPF supports [[Internet Protocol version 4]] (IPv4) and [[Internet Protocol version 6]] (IPv6) networks and is widely used in large [[enterprise network]]s. [[IS-IS]], another LSR-based protocol, is more common in large [[Network service provider|service provider]] networks.

Originally designed in the 1980s, OSPF version 2 is defined in  RFC 2328 (1998).{{Ref RFC|2328}} The updates for IPv6 are specified as OSPF version 3 in RFC 5340 (2008).{{Ref RFC|5340}} OSPF supports the [[Classless Inter-Domain Routing]] (CIDR) addressing model.

{{IPstack}}