On Fri, Jan 05, 2007 at 01:34:43AM +0000, Jefferson Ogata wrote:
>
> Think about what actually would happen in your desired scenario:
>
> 1. Remote client C sends a SYN packet from source endpoint C:P to
> service destination endpoint D:S, which resides on a translating box D.
> On the client, the socket is in SYN_SENT state with remote endpoint D:S.
>
> 2. Translating box receives SYN packet and translates destination to E:T
> and retransmits it to serving box E. So now the SYN packet is C:P -> E:T.
>
> 3. Serving box E receives the SYN packet and responds with a SYN/ACK
> from E:T -> C:P. The socket on the serving box is in SYN_RCVD state with
> remote endpoint C:P. Since the SYN/ACK destination C is remote, E sends
> the packet out through the default router, so the translating box D
> never sees this packet.
Could serving box E fake the source of that packet so it appears to
come from translating box D? Is that all that's needed to make
this work?
> 4. Client box C receives SYN/ACK from E:T and discards it, because it
> has no pending TCP connection in SYN_SENT state with E:T as the remote
> endpoint.
--
-Gary Mills- -Unix Support- -U of M Academic Computing and Networking-
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