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Eigrp + show ip interface = 224.0.0.10 still persists

psarantsev
Level 1
Level 1

Dear Colleagues,

Lets try to understand one little thing concerning EIGRP work.

Step-by-Step:

sh in s2/0 | incl 224.0.0.10 - i'm getting nothing and it's OK

!-then-!

conf t

router eigrp 1

network 1.1.1.0 (not so important)

passive interface s2/0

exit

exit

!-and then again-!

sh in s2/0 | incl 224.0.0.10 - i'm getting 224.0.0.10 - And it's NOT OK.

Why is interface still getting packets for that multicast address?

If it's OK for IOS. How can I deny any bogus updates comming from that interface, if someone sets TTL higher than 1.

Thanks in advance....

Sarantsev Pavel (CCNP)

SPV-RIPE

2 Replies 2

ruwhite
Level 7
Level 7

I'm not certain I completely understand the question (?). Are you saying you're disturbed by the router being able to receive packets on 224.0.0.10 while the interface is passive? This is the definition of a passive interface--I will accept packets for this protocol, I just won't send any. In eigrp's case, this means that you won't build an adjacency, since we rely on two way communication to get an adjacency up in eigrp.

:-)

Russ

Thanks for answer...

But still, here is smth from http://www.cisco.com/warp/public/103/16.html:

On most protocols, passive interface stops the router from sending updates to a particular neighbor, but continues to listen and use routing updates from that neighbor. However, on EIGRP, passive interface causes the router to stop sending and receiving hello packets.

Here is several questions:

1 - Why I'm still getting routing updates from that link (I had set that for passive because I DON"T WANT to do that &^)))))))))

2 - You may say that EIGRP doesn't do that... Allright... so here comes the second question: If It doesn't either send of receive updates... What is the use of still subsribing to 224.0.0.10 group ? &^))

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