nanog mailing list archives
Re: an effect of ignoring BCP38
From: Jo Rhett <jrhett () netconsonance com>
Date: Thu, 11 Sep 2008 10:25:01 -0700
On Sep 11, 2008, at 10:10 AM, Valdis.Kletnieks () vt edu wrote:
Part of the problem is that if you're talking about the 5 biggest providers, and the 5 biggest transit, you're talking about places with routing swamps big enough, and with sufficient dragons in residence, that you really *can't* do BCP38 in any sane manner. AS1312 (us) is able to do very strict BCP38 on a per-port level on every router port, because we *know* what's supposed to be on every subnet. By the time you walk our list of upstreams to any of the '5 biggest anything', you've gotten to places where our multihomed status means you can't filter our source address very easily (or more properly, whereyou can't filter multihomed sources in general).
I don't agree with this statement. I hear this a lot, and it's not really true. Being multihomed doesn't mean that your source addresses are likely to be random. (or would be valid if they were)
A significant portion of our customers, and *all* of the biggest paying ones, are multihomed. And they might have a lot of different ranges, but we know what the ranges are and filter on those.
The MIT Spoofer project seems to indicate that closer to 50% *of the edge* is doing sane filtering. And that's where you need to do it - *edge* not *core*.
I've said much the same myself. With the caveot that if you aren't doing it at the edge, you need to be doing it at the closest edge you can find.
-- Jo RhettNet Consonance : consonant endings by net philanthropy, open source and other randomness
Current thread:
- an effect of ignoring BCP38, (continued)
- an effect of ignoring BCP38 bmanning (Sep 04)
- Re: an effect of ignoring BCP38 David Sinn (Sep 05)
- Re: an effect of ignoring BCP38 k claffy (Sep 06)
- Re: an effect of ignoring BCP38 Valdis . Kletnieks (Sep 08)
- Re: an effect of ignoring BCP38 Jo Rhett (Sep 11)
- Re: an effect of ignoring BCP38 Pekka Savola (Sep 11)
- Re: an effect of ignoring BCP38 Jo Rhett (Sep 11)
- Re: an effect of ignoring BCP38 Pekka Savola (Sep 11)
- Re: an effect of ignoring BCP38 Jo Rhett (Sep 11)
- Re: an effect of ignoring BCP38 Valdis . Kletnieks (Sep 11)
- Re: an effect of ignoring BCP38 Jo Rhett (Sep 11)
- Re: an effect of ignoring BCP38 Pekka Savola (Sep 11)
- Re: an effect of ignoring BCP38 Kevin Oberman (Sep 11)
- Re: an effect of ignoring BCP38 Kevin Oberman (Sep 11)
- Re: an effect of ignoring BCP38 Valdis . Kletnieks (Sep 11)
- Re: an effect of ignoring BCP38 Randy Bush (Sep 07)
- Re: an effect of ignoring BCP38 bmanning (Sep 07)
- Re: an effect of ignoring BCP38 Randy Bush (Sep 08)
- Re: an effect of ignoring BCP38 Paul Vixie (Sep 08)
- Re: BCP38 dismissal Jo Rhett (Sep 04)
- Re: BCP38 dismissal Gadi Evron (Sep 04)