Which command can you use to display information about OSPF virtual links?
A. debug ip ospf adj
B. show ip ospf [process-id]
C. show ip ospf virtual-links
D. show ip ospf border-routers
The correct answer is show ip ospf virtual-links. The show ip ospf virtual-links command displays the
current state of OSPF virtual links, as shown below.
The following additional commands are available to verify OSPF configurations: show ip ospf border-
routers, debug ip ospf adj, and show ip ospf.
The show ip ospf border-routers command displays internal OSPF routing table entries for an ABR, as
router10#show ip ospf border-routers
Codes: i – Intra-area route, I-Inter-area route
Type Dest Address Cost NextHop Interface ABR ASBR Area SPF
i 18.104.22.168 10 22.214.171.124 Ethernet 2 TRUE FALSE 0 3
i 126.96.36.199 10 188.8.131.52 Ethernet 2 TRUE FALSE 0 3
The show ip ospf command displays information about the router’s role and each area to which the router is
connected, as shown below.
The debug ip ospf adj command displays information about the state of neighbor adjacencies, as shown
R3#debug ip ospf adj
OSPF adjacency events debugging is on
00:54:04: OSPF: Rcv pkt from 184.108.40.206, Ethernet0, area 0.0.0.1 : src not on
the same network
In the above example, either the IP address or the subnet mask is misconfigured on either this router or the
Layer 3 Technologies
Configure and verify network types, area types, and router types
Cisco > Cisco IOS IP Routing Protocols Command Reference > IP Routing Protocol-Independent
Commands: S through T > show ip ospf virtual-links