bgp dampened

[zaqtivi]

what do we mean when we say bgp is dampened ?

[Edison Ortiz]

When a route is dampened, it's being considered by the BGP process as too unstable to be used locally or advertised to any BGP peer.

[zaqtivi]

What commands can we run then so as to know that BGP is too unstable to be used locally ?

[mheusinger]

Hi,

have a look at RIPE documents 229 and 378, which explain in detail why dampening was used and why it is not recommended any more.

RIPE Routing Working Group Recommendations on Route-flap Damping

http://www.ripe.net/ripe/docs/ripe-378.html

Obsoleted by ripe-378 the original approach:

ftp://ftp.ripe.net/ripe/docs/ripe-229.txt

In brief: each time a path was withdrawn and then reannounced (a "flap") in BGP some penalty points were given. Once a configurable amount of penalty points was accumulated the path was suppressed, i.e. not used for a configurable amount of time. It is a kind of "educational system" to achieve BGP stability. Because the approach had considerable drawbacks (see RIPE 378) it is now not recommended to implement route flap dampening.

Hope this helps! Please rate all posts.

Regards, Martin

[gaurav.prakash]

Thx Martin,

So is there any alternative solution to achieve the objectives of route-dampening or its just like that ...

Regards,

Gaurav

[benjaminwang74]

Hi Martin,

So the current practice is not to implement route damping? Is there any configuration example you can provide us? I have done some look around, and unable to find anything beside a few thesis.

[Danilo Dy]

Hi,

As what Martin mentioned and the link he has provided, route flap dampening may more harmful than useful. However, it depends on the organization whether to remove it or keep/configure it as your mileage may vary.

Regards,

Dandy