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Re: an effect of ignoring BCP38
On Thu, 11 Sep 2008, Jo Rhett wrote:
I've been in, near, or directly in touch with enough big provider NOCs in the last year on various DoS attach research issues, and nearly nobody... that's right NONE of them were using BCP38 consistently. Name the five biggest providers you can think of. They ain't doing it. Now name the five best transit providers you can think of. They ain't doing it either. (note that all of these claimed to be doing so in that survey, but during attack research they admitted that it was only in small deployments)
A problem I have with these discussions is that everyone has their own idea what "BCP38" implies. Others say their loose-mode uRPF setups are "BCP38". Others are using strict uRPF or similar (e.g. acls). Some think that Tier1 transit operators should apply one of the options above to their tier2 customers. Others think it should just be applied at the site-edges. Some don't consider spoofing protection at LAN interface level at all, others call that also BCP38. Etc.
Your note above seems to imply that you would expect the five best transit providers you think of to apply BCP38 (strict?) to their customers. Even if the customer is a major ISP? (However, if your argument is about a smallish end-site, I'd agree spoofing protection should be applied there.)
FWIW, I've tested what would happen if I were to enable strict-mode (feasible paths) uRPF on an Internet exchange (all peerings). If I recall correctly, the amount of dropped packets would have been in the order of 1%. We decided not to do it. Maybe those "five biggest providers you can think of" have similar experiences with their biggest customers?
Loose mode URPF is seems (IMHO) pretty much waste of time and is confusing the discussion about real spoofing protection. The added protection compared to ACLs that drop private and possibly bogons is not that big and it causes transient losses when the routing tables are changing.
-- Pekka Savola "You each name yourselves king, yet the Netcore Oy kingdom bleeds." Systems. Networks. Security. -- George R.R. Martin: A Clash of Kings