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s.m
New Member

should FE be made passive (under ospf) with bgp session running

greeting.....

i have a bgp session running with another AS whose link is terminating on my FE0/1 interface.

i also have ospf running for my internal backbone netowrk.

under ospf configuration.....FE0/1 has been made a passive-interface.....

********************************************

router ospf xxx

summary-address 203.x.x.x 255.255.x.x

redistribute static subnets route-map locstatics

passive-interface FastEthernet0/1

**********************************************

Is this ok or should this command be removed.

I am concerned since this interface is running a bgp session with a neighbor AS....it should be receiving updates.....am i rite.....

kindly suggest......

appreciation in advance.......

3 REPLIES
New Member

Re: should FE be made passive (under ospf) with bgp session runn

First, "passive interface" does not stop an interface from receiving updates - only from transmitting them. Also, I beleive that it is protocol specific. You may not even need the statement though. I don't think OSPF would be active on FE0/1 unless there was a network statement in your OSPF setup that would encompass the IP on FE0/1.

s.m
New Member

Re: should FE be made passive (under ospf) with bgp session runn

thanks a lot scott.......i realsied it after i consulted a li`ll basics.......u were rite...my fe0/1 dosent needs updates from my other locations...

thanks pal

New Member

Re: should FE be made passive (under ospf) with bgp session runn

I need to correct myself a little just for the record in spite of the fact that your problem is solved.

It is true that passive interfaces can receive but not send updates. However, with a protocol like OSPF, you need a bidirectional link before routing updates can be exchanged. So, theoretically, OSPF could not receive updates if it were prevented from sending hellos. The authors of the CCNP book "BSCN" state that their in-house testing revealed that a passive OSPF interface does indeed send hellos. They didn't elaborate and say whether or not LSA received would be put into the database for consideration in the routing table. As for EIGRP, they say passive causes nothing at all to be sent (routing-wise) - presumably preventing any kind of neighbor relationship from being formed, and thus, updates from being received.

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