show ip ospf

show ip ospf
The show ip ospf command is used to display OSPF information for one or all OSPF processes
running on the router. Information contained therein includes the router ID, area information,
SPF statistics, and LSA timer information. Here is a sample output:
RouterA#sho ip ospf
Routing Process "ospf 1" with ID 172.16.240.1
Supports only single TOS(TOS0) routes
SPF schedule delay 5 secs, Hold time between two SPFs 10 secs
Number of DCbitless external LSA 0
Number of DoNotAge external LSA 0
Number of areas in this router is 1. 1 normal 0 stub 0 nssa
Area BACKBONE(0)
Number of interfaces in this area is 3
Area has no authentication
SPF algorithm executed 17 times
Area ranges are
Link State Update Interval is 00:30:00 and due in 00:17:52
Link State Age Interval is 00:20:00 and due in 00:07:52
Number of DCbitless LSA 0
Number of indication LSA 0
Number of DoNotAge LSA 0
RouterA#
show ip ospf border-routers
The show ip ospf border-routers command displays the process ID on the router, the route
to the ABR or ASBR, and the SPF information. Here is a sample output:
RouterC#show ip ospf border-routers
OSPF Process 1 internal Routing Table
Codes: i - Intra-area route, I - Inter-area route
i 172.16.240.1 [65] via 172.16.1.106, Serial1, ABR, Area 0, SPF 582
i 172.16.241.1 [65] via 172.16.1.94, Serial11, ASBR, Area 0, SPF 582
RouterC#
This is a simple output that shows only one ABR and one ASBR. In order to have an ABR, you
must have multiple areas configured. In order to have an ASBR, external routes on an external
172 Chapter 5  OSPF Operation in a Single Area
autonomous system must be connected to the router and redistributed from another routing protocol
into OSPF.