On Thu, 19 Dec 2002, David Scott Olverson wrote:
Hello all,
I was wondering if anyone was aware of a way to use the congestion of a network link to control the routing update. For example if I have a very small link that gets congested, I may want the router to withhold a routing update until link congestion falls below a certain threshold like 60% of bandwidth. Is anyone aware of anything like this available today or a technique that might accomplish something similar? You can contact me off list if this topic isn't germane.
The first thing that comes to my mind would be conditional announcements. You could have an internal routing server setup on a private ASN, which monitors the congestion with snmp. When congestion is occuring, inject a bogus route into BGP (say, 127.100.0.1/32, with different IPs to be injected depending on the link that is experiencing congestion). Configure your conditional announcements to NOT announce your routes over the particular link when the bogus route shows up. And of course, to prevent flapping, advertise your bogus routes for X minimum period of time after congestion dissapears. I can't see any reason why this wouldn't work or would be a poor idea... Andy (dills@hcs.harvard.edu...the HASCS guys hate me, I was a huge pain in the ass when I was an undergrad...still am, I guess) xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx Andy Dills 301-682-9972 Xecunet, LLC www.xecu.net xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx Dialup * Webhosting * E-Commerce * High-Speed Access