[Rant below. My apologies. Sometimes, your spleen needs a-ventin'.] I know I'm behind on this conversation, but I want to say that, for the record, Bellovin's presentation, and the resultant "You're not paying me for my routing table, you bastard" sentiment, drives me up a wall. BGP is for setting and sharing policy. If you don't want to listen to somebody else's legitimate policy, the right answer is not to filter that policy; the right answer is not to peer. If you're not interested in policy decisions, you can get static routes by examining the routing arbiters or even the registries' records. Despite what some venders want you to believe, memory is cheap, processors that can handle the Internet routing table are cheap, and the only really expensive things to build in a router are the high speed line cards and the forwarding engine(s) to push them. If we were running the Internet on 68020 processors over 56k and T1 lines still, you would have a point. But the additional load of allowing other people to set their policy as they see fit is not a relevant concern on modern equipment. There are lots of legitimate reasons for making announcements like this. One is backup connectivity; if the primary fails, and you're filtering the backup, you might not be taking the best path to the end user. In fact, if you're well connected, you're passing it off to the primary, who, if he is filtering as well, won't pass it off to the secondary, and if he's not filtering, you're transiting when you don't need to. At a bare minimum, you're putting the decision off to your provider, in which case, why are you peering in the first place? Another is load sharing; if I have 60MB of traffic for my site, and I have two T3s, I might set policy to try to equalize that data. If you ignore my policy, you might overload one of the links and not be able to reach my site. I suffer, your customers suffer, eveybody gets pissy, because you didn't have 2k of RAM to share with a fellow member of the Internet whose down on his luck. You should do this to be a good neighbor. You should do this to be charatable. You should do this because you might need it yourself someday. Now, before anybody gets the wrong idea, yes, I know there are people who announce their supernets as /24s or smaller because of technical incompetance. The ISPs should do what they can to prevent that; I know that we have historically been rat bastards to our customers who wanted to make smaller announcements and couldn't tell us why. And there are people who are running old hardware, or are being victimized by 800% markup by the vendor, or otherwise really cannot spare the cycles and the RAM to support other people's policy. You gotta do what you gotta do. But hogging cycles you aren't using, and memory that is sitting idle, on some sort of "You're not paying me" principle, is just absurd. -Dave On 6/9/2001 at 13:47:15 -0700, Randy Bush said:

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There are lots of reasons to have some diverse /22 announcements in your network for example. but if you are not paying me, what reasons are there for me to spend my resources (route bloat) so you can engineer your traffic? The fact that your other customers are paying you to reach everyone on the internet?

red herring alert! the point is not reachability. the aggregate is still available. see bellovin's phoenix presentation.

randy

-- Dave Israel Senior Manager, IP Backbone Intermedia Business Internet