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
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.
But anyway, it's very important to restrict outgoing traffic of the usial customers by their own SRC addresses. It's difficult to stop rocket when it's flying in the cosmic space, but it's easy to destroy in on the starting part of it's trace. (Remember about _strategin defence iniciative_ /I do not know it's name in english/ -:)). And this coud be realised by router's vendor easily. --- Aleksei Roudnev, Network Operations Center, Relcom, Moscow (+7 095) 194-19-95 (Network Operations Center Hot Line),(+7 095) 239-10-10, N 13729 (pager) (+7 095) 196-72-12 (Support), (+7 095) 194-33-28 (Fax)
participants (2)
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alex＠relcom.eu.net -
Vern Paxson