Blocking RIP updates ?

Answered Question
Mar 24th, 2008

Hi,

Is there a way to block RIP updates 'outbound' on a router interface ?

I realise that it is probably better to block them 'inbound' to save unnecessary processing. But I cannot get outbound to work. I am using the following acl :

access-list 100 deny udp any any eq rip

int e0

ip access-group 100 out

Regards,

Phil.

I have this problem too.
0 votes
Correct Answer by Jon Marshall about 8 years 8 months ago

Phil

Apologies Phil, didn't mean to patronise you.

No this won't work because an access-list applied outbound on an interface does not stop packets sourced by the router itself.

Jon

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Jon Marshall Mon, 03/24/2008 - 11:39

Hi Phil

You can use the "passive-interface" command to achieve this ie. from Cisco doc

=============================================

For RIP and IGRP, the passive interface command stops the router from sending updates to a particular neighbor, but the router continues to listen and use routing updates from that neighbor;

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Full link

http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a0080208748.shtml

HTH

Jon

philipbarker Mon, 03/24/2008 - 11:44

Thanks John,

I understand the passive-interface operation. Can you confirm if it is or isn't possible though to filter the udp broadcasts 'outbound' a router interface ?

Regards,

Phil.

Correct Answer
Jon Marshall Mon, 03/24/2008 - 11:56

Phil

Apologies Phil, didn't mean to patronise you.

No this won't work because an access-list applied outbound on an interface does not stop packets sourced by the router itself.

Jon

philipbarker Mon, 03/24/2008 - 12:18

Hi John,

No need to apologise. I am just trying to do things in as many different ways as possible so that my options remain open.

Regards,

Phil.

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