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computer A( needs to establish a UDP connection to computer C(

As you can see both are on a different subnetwork. Now I have computer B which has 2 IP addresses, one for each subnetwork ( and A can ping B and B can C but A cant ping C. How can I use computer B to establish the connection between A and B. Remember that computer A needs to connect with a program I made so I cant do any command line stuff. Would port forwarding work? How would I do this?

Im thinking of doing SSH -L 10002: but then even if this works will I still have create another forwarding so that communication will go both ways?

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There's probably a mistake in your question, since both computers A and C are on network – ℝaphink Dec 23 '09 at 18:26
your right my bad that was a typo – user16654 Dec 23 '09 at 18:32
Which O/S are A/B/C? – harrymc Dec 23 '09 at 18:48
A= windows B=Ubuntu C= no OS its an embedded device without any OS – user16654 Dec 23 '09 at 18:50
Each machine, or its default router, must know to use the gateway to reach machines on the other subnet. – David Schwartz Mar 28 at 20:49

i think you just have to enable packet forwarding on computer B. For example on Ubuntu that is done by running:

echo 1 > /proc/sys/net/ipv4/ip_forward

Now the computer can take packets received on one interface and send them out on another interface.

Edit: On Ubuntu that doesn't work with sudo, I had to use "sudo su" and then run the above as root.

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thx i'll give it as try – user16654 Dec 23 '09 at 18:51
there is only one interface though – user16654 Dec 23 '09 at 19:05
can you post the outputs of "ifconfig" and "route", please? – Nick Dec 23 '09 at 19:12
Check A's "route" as well. Does it have a route (host, network or default) for a packet bound for C ( And does C by default forward everything to B? – shank Dec 23 '09 at 20:18

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