“OSPF is a link-state based routing protocol. It is designed to be run internal to a single Autonomous System. Each OSPF router maintains an identical database describing the Autonomous System’s topology. From this database, a routing table is calculated by constructing a shortest-path tree. OSPF recalculates routes quickly in the face of topological changes, utilizing a minimum of routing protocol traffic. OSPF provides support for equal-cost multipath. An area routing capability is provided, enabling an additional level of routing protection and a reduction in routing protocol traffic.” –rfc1247
Enable an OSPF instance:
switch(config)# router ospf INSTANCE [vrf NAME] switch(config-ospf)# router-id ROUTER
Configure an OSPF area:
switch(config-ospf)# area AREA [stub|nssa|default-metric COST] Configure external
Route redistribution and control:
switch(config-ospf)# redistribute <bgp|connected|static>
switch(config-ospf)# default-metric VALUE switch(config-ospf)# maximum-paths VALUE
Influence route choice by changing the administrative distance:
switch(config-ospf)# distance VALUE
Enable OSPF on an interface:
switch(config-if)# ip ospf PROCESS-ID area AREA
Configure optional OSPF interface settings:
switch(config-if)# ip ospf cost COST
switch(config-if)# ip ospf hello-interval SECONDS
switch(config-if)# ip ospf dead-interval SECONDS
switch(config-if)# ip ospf retransmit-interval SECONDS
switch(config-if)# ip ospf transit-delay SECONDS
switch(config-if)# ip ospf network <broadcast|point-to-point>
switch(config-if)# ip ospf priority VALUE
switch(config-if)# ip ospf <active|passive>
switch(config-if)# ip ospf bfd
Configure OSPF interface authentication:
switch(config-if)# ip ospf authentication <message-digest|simple-text|null> switch(config-if)# ip ospf authentication-key PSWD
switch(config-if)# ip ospf message-digest-key md5 <cipher|plain>text KEY
Show commands to validate functionality:
show ip ospf [interface|neighbors]
show ip route ospf
show commands looks correct