Re: BGP Update Report

[Anton Kapela <tkapela () gmail com>]

Joe,

> The problem is that unless one is holding customer routes in a 
> seperate VRF and dampen them there or take similar steps to 
> segment, dampening leads directly to blackholes.  Even in that
> case, failover within that VRF wouldn't work, as all 
> implementations I've seen attack the prefix as the problem instead
> of the path vector. Bye-bye alternate paths.  

I guess what I'm hinting at is precisely something finer-grained (path not prefix), as you suggest. Per-neighbor 
enabled, versus "entire bgp RIB" would be preferred. I'm also interested in the *chronic* nature of these apparent 
instabilities. An average of one flap per minute could imply that the end-site is not getting allot of useful TCP 
moved, and as such, after something on the (n)-hour timescale, perhaps it's worth suppressing it.

So, I'd ask for a long-timescale dampening function, indexed against per-path, and enforced per neighbor. Perhaps 
as-path lists could be combined with relaxed timers on existing implementations to achieve this today (in a VRF 
target/context). 

-Tk