OSPF Demand Circuit

Zup!?  Here Again.

According to the Solution the config can be applied on R9 only and R7's  show ip ospf interface gigabitEthernet1.79 output the interfaces

appears as demand circuit.  On my case that is true when I change the network type to Point-to-Point.  But while in broadcast only R9 appears

as "Configured as demand circuit" .   I'm assuming it will be common sense to think this should be the normal behaviour, since on a Broadcast Net

there could be more than one Routers and not all might be sending the OD-circuit option within thier LSA's.  In addition OD circuit was introduced for dial/point-to-point networks.  Is this correct?


Could this be a BUG on the CSR ?


R7#show ip ospf interface gigabitEthernet1.79
GigabitEthernet1.79 is up, line protocol is up
Internet Address, Area 2, Attached via Network Statement
Process ID 1, Router ID, Network Type BROADCAST
, Cost: 1
 Topology Name
 Base Configured as demand circuit
Run as demand circuit
DoNotAge LSA allowed



  • I have the same doubt

    Only enabling network point-to-point i can see DNA bit on LSAs and enabling ospf ond demand on one side...


    Any update?

  • Same here.
    when enabling only on demand-circuit under Gi1/0.79 on R9, the output of the command 'show ip ospf interface Gi1/0.79' on R7 does not show
    **Run as demand circuit
    DoNotAge LSA allowed **

    It is only after configuring the network type as point-to-point on Gi1/0.79 on both routers, R7 nd R9, that the 'show ip ospf interface Gi1/0.79' on R7 shows
    **Run as demand circuit
    DoNotAge LSA allowed **

    Is the above the expected behaviour and there is an error in the lab or is it something that I am doing wrong?


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