Changing BGP AD on routes from specific AS

[dlongworth]

Hi All.

Is it possible to change the Admin Distance on eBGP routes (using 'Distance' cmd, I guess), but only from a specific AS?

IOS 12.2SX

I guess what I'm looking for is the Distance cmd to reference a route-map instead of an ACL.

Cheers

David

[royalblues]

David,

What is the need for changing the AD for Ebgp for some specific routes?

If you are trying to do this to modify routing preference, then there are lot of other attributes which you can use with BGP

Narayan

[dlongworth]

Hi Narayan,

I have a preference for certain EIGRP routes to be chosen over their BGP equivalents but it'd be simpler if I could reference the origination AS instead of a few hundred routes.

[Edison Ortiz]

In that case you can do it under EIGRP but only for internal EIGRP routes, you can't do it under the BGP routing process.

See a sample in my lab:

I want to make 10.1.2.2 an EIGRP route:

Rack1R1#sh ip route

Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP

D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area

N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

E1 - OSPF external type 1, E2 - OSPF external type 2

i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2

ia - IS-IS inter area, * - candidate default, U - per-user static route

o - ODR, P - periodic downloaded static route

Gateway of last resort is not set

192.168.12.0/30 is subnetted, 1 subnets

C 192.168.12.0 is directly connected, Serial1/0

20.0.0.0/32 is subnetted, 1 subnets

B 20.1.2.2 [20/0] via 192.168.12.2, 00:03:41

10.0.0.0/32 is subnetted, 1 subnets

B 10.1.2.2 [20/0] via 192.168.12.2, 00:03:41

150.1.0.0/32 is subnetted, 1 subnets

B 150.1.2.2 [20/0] via 192.168.12.2, 00:03:41

____________________________

access-list 1 permit 10.1.2.2

router eigrp 1

network 192.168.12.1 0.0.0.0

distance 19 192.168.12.2 0.0.0.0 1

no auto-summary

_______________________________________

Rack1R1#sh ip route

Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP

D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area

N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

E1 - OSPF external type 1, E2 - OSPF external type 2

i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2

ia - IS-IS inter area, * - candidate default, U - per-user static route

o - ODR, P - periodic downloaded static route

Gateway of last resort is not set

192.168.12.0/30 is subnetted, 1 subnets

C 192.168.12.0 is directly connected, Serial1/0

20.0.0.0/32 is subnetted, 1 subnets

B 20.1.2.2 [20/0] via 192.168.12.2, 00:03:51

10.0.0.0/32 is subnetted, 1 subnets

D 10.1.2.2 [19/2297856] via 192.168.12.2, 00:00:07, Serial1/0

150.1.0.0/32 is subnetted, 1 subnets

B 150.1.2.2 [20/0] via 192.168.12.2, 00:03:51

___________________________________

HTH,

____

Edison.

Please rate helpful posts

[dlongworth]

That does help, thank you, but unfortunately I do need it also for EIGRP external routes.

[Edison Ortiz]

Hi David,

Too bad, this can only be done with internal EIGRP routes.

You can't use the distance command within a route-map for BGP routes.

__

Edison.

[mrosasco]

Hi.

you can use the network backdoor command, under bgp, for this routes.

It's for this problem.

Regards

[sdoremus33]

Perhaps you could use the network backdoor command to influence the route