CCIE Pursuit Blog

April 16, 2008

Question Of The Day: 16 April, 2008

Topic: OSPF

Which OPSF area is interface Fa0/0 in?

r1#sh run | sec router ospf|net0/0
interface FastEthernet0/0
 ip address
 ip ospf 100 area 3
router ospf 100
 network area 2
 network area 1
 network area 0

Click Here For The Answer

Yesterday’s Question

Question Of The Day: 15 April, 2008 

Topic: OSPF

You get a call from the NOC.  The NMS application is reporting tons of alerts on r1.  After inspecting the alerts you determine that they are being caused by r1 receiving Type 6 LSAs.  How would you configure r1 to stop these alerts?

Answer: Configure ‘ignore lsa mospf’ under the OSPF process of r1.

ignore lsa mospf

To suppress the sending of syslog messages when the router receives link-state advertisement (LSA) Type 6 Multicast OSPF (MOSPF) packets, which are unsupported, use the ignore lsa mospf command in router configuration mode. To restore the sending of syslog messages, use the no form of this command.

Cisco routers do not support LSA Type 6 MOSPF packets, and they generate syslog messages if they receive such packets. If the router is receiving many MOSPF packets, you might want to configure the router to ignore the packets and thus prevent a large number of syslog messages.

In our example we would configure the following:

router ospf 100
  ignore lsa mospf



  1. […] Click Here For The Answer […]

    Pingback by Question Of The Day: 15 April, 2008 « CCIE Pursuit — April 16, 2008 @ 10:26 am | Reply

  2. It looks like enabling OSPF and defining the area explicitly on the interface takes precendence over the area defined by any of the network statements for the defined OSPF process id. That being said, the Fa0/0 interface is in OSPF area 3.

    Comment by Steve — April 16, 2008 @ 11:55 am | Reply

  3. BTW-thank you so much for posting these questions of the day, they are a very very useful and much appreciated exercise.

    Comment by Steve — April 16, 2008 @ 12:25 pm | Reply

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