[4307] in North American Network Operators' Group
Re: SYN floods continue
daemon@ATHENA.MIT.EDU (Vern Paxson)
Wed Sep 11 16:43:51 1996
To: Vadim Antonov <avg@quake.net>
Cc: alex@relcom.EU.net, jon@branch.com, jtk@nap.net, alexis@panix.com,
nanog@merit.edu
In-reply-to: Your message of Wed, 11 Sep 96 12:33:02 PDT.
Date: Wed, 11 Sep 96 13:39:19 PDT
From: Vern Paxson <vern@ee.lbl.gov>
> That prohibits IP src spoofing (and asymmetrical paths).
> ...
> In most networks asymmetrical routing is an indication of a bug in
> an IGP configuration, so early detection of the configuration problems
> would be an additional benefit.
In my Internet end-to-end routing study I found that fully 50% of the pairs
of paths through the Internet had a major asymmetry at the end of 1995.
"Major" meaning: visited at least one different city in the two directions.
(30% visited at least one different AS.) This was a significant increase
over the same figure for the end of 1994, 30%. So it may be quite hard to
make and keep Internet routing symmetric.
The paper's available from:
ftp://ftp.ee.lbl.gov/papers/routing.SIGCOMM.ps.Z
- Vern
