Friday, October 3, 2008

RIP - route filtering options


3 ways to filter routes with an even 3rd octet: distribute-list, distance and offset-list

For the distribute-list command I create an acl that matches the routes I want to allow

ip access-list standard 1
permit 0.0.1.0 255.255.254.255



Distribute-list
router rip
distribute-list 1 in


Distance
router rip
distance 255 204.12.5.1 0.0.0.0 1


where 204.12.5.1 is the next hop of the route to be poisioned

For the offset-list commands I create an acl that matches routes I want to block

ip access-list standard 2
permit 0.0.0.0 255.255.254.255


Offset-list
router rip
offset-list 1 in 16

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