* Valdis.Kletnieks@vt.edu <Valdis.Kletnieks@vt.edu> [20010206 21:02]:
So - who wants to crunch the numbers and figure out how many of those 58K are useless punchouts ("Route all of 128.257.x.x to me, except for 128.257.219.x, which also goes to me")....
Uhm, except that many punchouts are done so that someone else can *originate* announcements for that block and control their own metrics. Likely the ASN announcing 128.257.x.x is one of those still transitting traffic for that punched out network, but they no longer are the origin for the more specific announcement. In this way, the utilizer of the more specific can do things like prepending or whatever they like. It is fairly common when someone multihomes with non-ARIN space. If they pull IP space from one of their upstreams, they need to be able to announce equally specific /x routes via both or suffer funky inbound traffic patterns. This isn't possible if the upstream the space is from doesn't do the punchout for them. Considering how many multihomed sites there are without justification for a </19 (or /20) how else do you suppose they gain control over their announcements? So a more accurate way to figure out how many of those 58K are useless punchouts would be to first ask for the ones that say "Route all of 128.257.x.x to me, except for 128.257.219.x, which also goes to me" then to see if 128.257.219.x is also being announced via any other transit providers. Unless I'm misreading the punchouts you are referring to. Additionally, it remains impossible to *truly* know the intent of someones routing policy without asking them. I mean, some people could have funky routing backup scenarios that routing announcements that look odd to all of us looking into their network. I'm not saying they are right or they are wrong -- I'm saying it is difficult to tell unless you understand the reason behind every single ASNs announcement choices. Granted, some ASNs have no idea themselves. But how can you tell the difference between those ones and the ones with legit reasons? Nonetheless, none of these reasons are excuses to announce useless stuff that could be aggregated beyond your ASN. We need to continue work on infinite IP space and a scalable inter-AS routing protocol to match. That way, as long as you aren't announcing any networks that aren't yours, I don't care how mangled your announcements are to me. :-) -jr ---- Josh Richards [JTR38/JR539-ARIN] <jrichard@geekresearch.com/cubicle.net/fix.net/freedom.gen.ca.us> Geek Research LLC - <URL:http://www.geekresearch.com/> IP Network Engineering and Consulting