Viewing the OSPF Neighbor Table

The OSPF page lists the characteristics for the selected device if it is running the Open Shortest Path First protocol, a popular internal gateway routing protocol. The Device Viewer OSPF page divides into these two tables:

• OSPF Area Table: Listing the OSPF administrative Areas to which the router belongs.

• OSPF Neighbor Table: Listing all routers and router interfaces to which the current router has established OSPF adjacencies and exchanged link-state databases.

The OSPF Area Table panel displays the following relevant data columns:

• Area: The OSPF administrative networks to which the router belongs. In many circumstances, an OSPF router may belong to two or more Areas, including the Area0 backbone.

• AreaID: The dotted-quad version of each OSPF area ID.

• Authentication Type: The authentication protocol, if any, employed by the OSPF router in that specific Area.
  OSPF authentication operates on a point-to-point basis, usually using MD5 hashing.

• AS External Type: Indicates whether the area in which the router is participating is a standard Area or a Stub area.

• Border Router Count: Indicates the number of OSPF area border routers in each local area. Such routers are typically area border routers (ABRs) or Autonomous System border routers (ASBR).

• Route Table Calcs: The number of incidences where the router has been forced to run the Dijkstra algorithm on the network, to calculate the SPF database for the Area. Ideally, the value in this field should read zero or close to zero, indicating that no recalculations have been necessary since the router joined the OSPF Area. If a router experiences issues or an unstable link (flapping), higher numbers of recalcs are an indicator.

• Autonomous System Count: The number of ASes in which each Area in the Area Table operates.

• Link-State Advertisements: The number of link-state advertisements (LSAs) the router has sent to other neighbors during the course of information exchanging with other OSPF routers.

• Link-State Checksum: The checksum value listed in the device's router link-state advertisement header.

• Network View: Shows the NetMRI network view containing the local VRF or VRFs associated with the listed OSPF area.

The OSPF Neighbor Table displays the following information:

• Neighbor Name: The discovered name of the OSPF neighbor router.

• Neighbor IP Address: The IP address of the adjacent neighboring interface.

• Network View: Lists the NetMRI network view associated to the device's interface that connects to its discovered OSPF neighbor. Clicking the link opens the Network View Viewer window, which lists the AssociatedVRFs and the ImportedVRFs for the network view.

• Neighbor Router ID: The configured Router ID for the neighboring OSPF router (different value from the neighboring interface).

• Neighbor State: In a functioning OSPF adjacency, this value will show as Full.