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Parameter Description
IP Address The IP address of this OSPF interface.
Router ID Router ID for this router.
Designated
Router
The IP of the designated router. The designated router advertises the
link state of the OSPF Area.
Backup DR The backup designated router. If the designated router fails, the
backup designated router takes its place.
Status This interface’s status in this OSPF area.
Events The number of events since the designated router was selected.
Displaying the Link State Table
The link state table displays all advertisements in the link state database. This database
contains linkage information for all the areas to which this router is attached. Note that
all the routers within an area exchange information to ensure that they maintain an
identical link state database. This database can therefore be used to troubleshoot
network configuration problems.
Parameter Description
Area ID An OSPF area identifier configured for a group of OSPF routers. (For
information on how to assign this identifier to a specific interface, see
chapter 3 “Configuring OSPF”.)
Type The link state advertisement type:
RtrLSA: Router LSA – All area routers advertise the state of links
from the router itself to the its local area.
NetLSA: Network LSA – The designated router for each area
advertises the link state for each transit area; i.e., an area
with more than one attached router. This LSA includes
information about each router attached to the area,
including the designated router itself.
SumLSA: Summary LSA – Advertise the cost to a specific
subnetwork outside the router’s area, or the cost to a
specific autonomous system boundary router.
ExtLSA: External LSA – Advertises link state information for each
known network outside the autonomous system.
Link State ID The identifier for the router originating this entry, usually in the form of
an IP address.
Router ID The IP address of the originating router.