flapping eBGP peer - delay BGP peer routing

r.geranio · ‎02-17-2009

Hi.

I have two Internet routers on the same AS. Each router has one eBGP peer to an ISP. The ISP's are differnet AS. One is a Primary, the other a Secondary. My two Internet routers talk to each using iBGP and OSPF. I use pre-pend AS inbound on the Secondary so as to prefer the Primary ISP. We conditionally advertise to the Secondary ISP when we lose routes from the Primary ISP.

If the Primary eBGP goes down for whatever reason and then comes up, I want to remain on the Secondary for a fixed period of time and delay the time before preferring routes from the Primary and before beginning to advertise to the Primary.

Is there a design that can achieve this?

Istvan_Rabai · ‎02-17-2009

Hi Robert,

You may consider BGP route dampening:

http://www.cisco.com/en/US/docs/ios/iproute/configuration/guide/irp_bgp_adv_features_ps6441_TSD_Products_Configuration_Guide_Chapter.html#wp1056297

On this link you should look for the following sections:

BGP Route Dampening

Configuring BGP Route Dampening

Cheers:

Istvan

guruprasadr · ‎02-18-2009

HI Robert,

The BGP Route Dampening would/will work.

Use Pently feature of the BGP Route-Dampening feature.

Best Regards,

Guru Prasad R