On Mon, Nov 16, 2009 at 8:37 PM, Noel Chiappa <j...@mercury.lcs.mit.edu> wrote: > > From: Michael Menth <me...@informatik.uni-wuerzburg.de> > > > it touches a fundamental problem of Loc/ID split solutions based on > > address rewriting when hosts have only a single local address but their > > edge network is multhomed to the outside world. > > I'm not sure I understand what the problem is; can you explain in a little > more detail?
Hi Noel, A is a client talking to a multihomed server B. Ip addresses: A: 1 B: 2 (internal) 3, 4 (external) Round trip from A to B: A picks address 3 via DNS. A->(1,3)->(1,2)->B->(2,1)->[(3,1),(4,1)]->A The problem is that A received a return packet from B that might have been from 3 and might have been from 4. But A has no idea what to do with a packet from 4. Per Michael, the solution is either: 1. Stateful NAT. The translator on B's network handles both network paths and remembers that the communication from A came to destination 3 so that he can put source 3 back on the outbound packet. 2. Host modification. The inbound NAT adds an IP extension with the original destination address. The host echos this in the return packet, providing the outbound NAT with the info he needs to set the correct external source address. Regards, Bill Herrin -- William D. Herrin ................ her...@dirtside.com b...@herrin.us 3005 Crane Dr. ...................... Web: <http://bill.herrin.us/> Falls Church, VA 22042-3004 _______________________________________________ rrg mailing list rrg@irtf.org http://www.irtf.org/mailman/listinfo/rrg
