more specific routes in today reality
Havard Eidnes he at uninett.no
Wed Oct 10 22:16:38 CEST 2001
> > So what are you refering to? Please name examples of your wild claim: > > Okay, let's see if i find it: > > 192.124.115.0/24 == weblease AG, old address space from pre-ARIN, > region should be ARIN/USA, is used in DE (okay -- no direct /16 or > smaller announcement) [...] Right. Routing is more or less orthogonal to assignment or allocation policies. There's no general route 192.0.0/8 in the default-free zone, so one or more providers in the default-free zone stopped listening to prefixes longer than, say /20, packets from those providers' customers towards e.g. 192.124.115.0/24 would be dropped on the floor by the first router along the path which didn't have a default route. > [...], but an example of the bad usage in the swamp space. > > inetnum: 194.13.111.0 - 194.13.111.255 > > route-server>sh ip bgp 194.13.111.0/24 shorter-prefixes > * 194.13.0.0/17 12.123.25.245 0 7018 3549 1103 1103 i The routes 194.13.111.0/24 and 194.13.0.0/17 have different origin ASes, 1103 and 5409, respectively. My guess is that the originator of the 194.13.0.0/17 prefix is being a Good Guy, since he probably figures that he has the majority of the address space covered by that prefix, he originates that single /17 route instead of deaggregating to cover the exact address space he has allocated locally. If that /24 route should vanish from the network, traffic towards that prefix would be sent in the direction indicated by the enclosing /17, but there is in all probability no connectivity between the two networks, so the traffic would be dropped on the floor when it came within the zone of the /17-originators network (but the /24 route is gone, possibly due to an outage, so who cares?). And your point was what, again? Regards, - Håvard
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