Re: Filtering http packet

Robert Sanders (rsanders@mindspring.net)
05 Aug 1997 14:16:44 -0400

This hardly seems the right place for this conversation, but...

"Graeme Slogrove" <graeme@fast.co.za> writes:

> No, the returned data from the HTTP server will not come from port
> 80. You must all all data from that server to be returned. Don't

Incorrect. The data sent from the HTTP server will indeed arrive in
packets with a source port of 80, or whatever destination port number
upon which the original request arrived. The identity of a TCP
connection is the 4-tuple of (src IP address, src port) + (dst IP
address, dst port). Port numbers cannot change once a connection has
been established. This is basic TCP, easily confirmed with a copy of
the RFCs, Stevens, or tcpdump.

regards,
-- Robert