Randy Bush wrote:
To move along an other tangent... What is the general wisdom on putting pull-ups on route annoucements to deter route flap?
I don't know about the general wisdom, but Internet Africa (not a North American operator) uses pull-ups for all routes that belong to single-homed customers. We figure that there's no reason for BGP speakers around the world to hear the flap when one of our single-homed customers drops a route.
Hence, you won't get the !H until you get to our border. Los pobre packitos will travel all the way and then get whacked. Seems to subvert one interpretation one could read into the intent of BGP.
I don't have stats, but I don't worry about the added load. TCP backs off pretty quickly when it figures out that the packets aren't getting through. Poorly-behaved UDP applications are another story, of course, but we hope there's not too much of that. --apb (Alan Barrett)