nanog mailing list archives
Re: Filtering levels (was RE: multi-homing without the BGP (was RE: Packet Loss))
From: "Daniel L. Golding" <dan () netrail net>
Date: Sun, 17 Dec 2000 10:14:40 -0500 (EST)
Travis, By doing a summary-only aggregate, you can lose routing information that your downstreams want seen by the global internet. A good example of this is prepending. If I only advertise a /14, then supress a /24 that is subordinate to that block, I may fail to advertise a prepend upon that /24 block. Paying customer don't like stuff like that. BTW, ARIN is pretty clear that it's allocation policies are NOT intended for use as filtering criteria. Most folks seem to get along fine, filtering at the /24 level. It's not like most core routers at large ISPs are 7500s with 64mb anymore. - Daniel Golding On Sun, 17 Dec 2000, Travis Pugh wrote:
On Sun, 17 Dec 2000 nanog () rmrf net wrote:Depends on what class it's in. Let me explain further. Verio, in their infinite wisdom, has decided that they are going to throw CIDR right out the window. We own 64.240.0.0-64.242.255.255. We advertise MANY smaller blocks of this space obviously, and what we have found is that in that space (since it is "Class A" space, remember we don't know what CIDR is since we're Verio) is that Verio does not accept anything smaller than a /20. Now many of our customers run BGP with us and advertise a /24 only, I guess they're SOL as far as Verio is concerned (actually if it's our space they're probably going to see the larger aggregate as well, so it's not as big of a deal, but still mighty annoying). Oh, and did I mention that Verio isn't even one of our peers? Oh well.Maybe if you aggregated your announcements instead of feeding a /14 to us as /22, /23, and /24 blocks, it wouldn't be necessary to do minimum-allocation filtering. -travis
Current thread:
- multi-homing without the BGP (was RE: Packet Loss) Jade E. Deane (Dec 15)
- RE: multi-homing without the BGP (was RE: Packet Loss) Daniel Golding (Dec 15)
- Filtering levels (was RE: multi-homing without the BGP (was RE: Packet Loss)) Jonathan Disher (Dec 15)
- RE: Filtering levels (was RE: multi-homing without the BGP (was RE: Packet Loss)) Daniel Golding (Dec 15)
- Re: Filtering levels (was RE: multi-homing without the BGP (was RE: Packet Loss)) nanog (Dec 16)
- Re: Filtering levels (was RE: multi-homing without the BGP (was RE: Packet Loss)) Travis Pugh (Dec 17)
- Re: Filtering levels (was RE: multi-homing without the BGP (was RE: Packet Loss)) Daniel L. Golding (Dec 17)
- Re: Filtering levels (was RE: multi-homing without the BGP (was RE: Packet Loss)) Travis Pugh (Dec 17)
- Re: Filtering levels (was RE: multi-homing without the BGP (was RE: Packet Loss)) Daniel L. Golding (Dec 17)
- Filtering levels (was RE: multi-homing without the BGP (was RE: Packet Loss)) Jonathan Disher (Dec 15)
- RE: multi-homing without the BGP (was RE: Packet Loss) Daniel Golding (Dec 15)