OSPF (Open Shortest Path First)

OSPF (Open Shortest Path First) is a link-state routing protocol that was defined in RFC 2328 in 1998. It is one of the most widely used Interior Gateway Protocols (IGP). It is frequently used in conjunction with BGP for MPLS networks. It is used to route within a single routing domain (i.e., autonomous system - AS) and BGP is used to interconnect autonomous systems. OSPF Version 2 is limited to IPv4. When utilizing OSPF for routing within a regional ESInet, it is a best practice to utilize OSPF Version 3 which includes support for IPv6.

NENA-INF-016, NENA Emergency Services IP Network Design (ESIND) Information Document

RFC 2328, OSFP Version 2