OSPF finite state machine

Reference: Routing TCP/IP 2nd Edition Jeff Doyle, page 353-357. OSPF router goes through several states before adjacency is formed. DOWN - No hello packets was seen from the neighbour router since the last dead interval. If an OSPF router goes to DOWN state from its higher states, its link state retransmission, database summary and link … Continue reading OSPF finite state machine

Understanding OSPF

Open Shortest Path First is using Djikstra's shortest path first algorithm. It is a link-state routing protocol, another link-state routing protocol is Intermediate System to Intermediate System also known as IS-IS. General facts about OSPF 1. Uses its own transport protocol number 89. Protocol number 89 indicates that this packet is destined for OSPF. 2. … Continue reading Understanding OSPF