----- Original Message -----
From: "bopolissimus X platypus Jr" <[EMAIL PROTECTED]>
To: "PLUG" <[email protected]>
Sent: Monday, April 10, 2006 11:12 PM
Subject: [plug] session marking question
If the client has its own IP, then there's no problem. But what if the
client is behind NAT? or some sort of proxy, SOCKS or squid? Is it
possible to mark the router's replies to the client so that the client
will reply with similarly marked packets, thus making it possible to
identify clients behind NAT?
yes you can still mark it... thru 4-tuple technique (source ip, source port,
destination ip and destination port for TCP and UDP.. for ICMP it uses icmp
types and code).... it usually used by NAT, load balancing, others and
perhaps yours for connection tracking...
Ideally, what I'm looking for is, if a client has authenticated himself,
I can put some extra information into the reply's header such that
the client will reply in an identifiable way (e.g., with a related
header entry that i can correlate with the mangled header that i sent
over to it). I realize that this may be a fools errand, just thought
I'd ask though, in case there's a way.
you will violate some RFCs if you modified or put extra information on the
header that doesnt conform to those RFCs...
Note: the mangling (if that's possible, or whatever other manipulations)
will run on a router. the router won't be able to manipulate the packet
payload, only the packet headers.
note that you can mangle the headers (eg. ip header, tcp header, udp header
and icmp header) subject to no violation occurs but you cant add extra bytes
or information in it unless you still conform with the RFC standards...
if you can give us a clear picture what you really intended to do (perhaps
your actual project)... we gladly to help you more...
fooler.
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