Indeed. All of this is the same for the DSCP actually, and the assumption is that operators will protect themselves with admission control.
(See sections 7.1 of RFC 2474 and 6.1 of RFC 2475 for detailed discussion) Brian "Steven M. Bellovin" wrote: > > In message <[EMAIL PROTECTED]>, Gerard.Gastaud@alc > atel.fr writes: > > > > > > > > >and the user may refuse to pay because it idid not ask for the flow label > that the malicious entity overwrote > > An enemy who is overwriting flow labels could generate fake packets > with arbitrary flow labels. It's strictly easier -- instead of > deleting and reinserting packets, you just generate them, with any > fields you want. > > If the routers can't cryptographically verify every flow labeled-packet > -- and they can't do that in any rational fashion, I suspect -- then > the only other choice is border control. Your border routers -- > including the peering routers, if necessary -- have to check that > incoming packets are, in some sense, "legal". In particular, if you're > going to charge someone extra for such services, you have to ensure > that the right party sent the packets. (This creates an interesting > problem at peering links -- what do you do with packets that have a > legal flow label for the peer, but not for you?) > > --Steve Bellovin, http://www.research.att.com/~smb > Full text of "Firewalls" book now at http://www.wilyhacker.com -------------------------------------------------------------------- IETF IPng Working Group Mailing List IPng Home Page: http://playground.sun.com/ipng FTP archive: ftp://playground.sun.com/pub/ipng Direct all administrative requests to [EMAIL PROTECTED] --------------------------------------------------------------------
