EIGRP to BGP Route-map question

[Vinayaka Raman]

Existing Configuration:

router bgp 65457

redistribute eigrp 1 route-map xxxx

route-map xxxx, deny, sequence 5

Match clauses:

   tag 65000 4809

Set clauses:

Policy routing matches: 0 packets, 0 bytes

route-map xxxx, permit, sequence 999

Match clauses:

Set clauses:

Policy routing matches: 0 packets, 0 bytes

show ip route 10.48.51.0

Routing entry for 10.48.48.0/22

New configuration to be added:

ip prefix-list IP_Route seq5 permit 10.48.51.0/22

route-map xxxx deny 6

ip address prefix-list IP_Route

Please note the prefix list does not have a correct network ID (the correct one is 10.48.48.0/22)

Can you tell me what would be the impact of inserting this route-map seq 6?

[Giuseppe Larosa]

Hello Vinayaka,

> Can you tell me what would be the impact of inserting this route-map seq 6?

The new route-map clause will be inserted after the clause with sequence 5

The matching IP prefix, if it exists, 10.48.48.0/22 will be denied from redistribution from EIGRP into BGP and a BGP advertisement for the same prefix will be withdrawn.

There shouldn't be an impact other then this

Hope to help

Giuseppe

[Peter Paluch]

Hello Vinayaka,

The router will silently mask the address argument in the prefix-list entry with the mask, and configure the resulting appropriate network. See for yourself:

R1(config)#ip prefix-list IP_Route seq 5 permit 10.48.51.0/22
R1(config)#do show run | inc prefix-list
ip prefix-list IP_Route seq 5 permit 10.48.48.0/22
R1(config)#

So the behavior of the route-map should be completely normal, according to its individual blocks:

• Routes tagged with either 65000 or 4809 will be denied
• Exact route 10.48.48.0/22 will be denied
• Other routes will be permitted

Best regards,

Peter