Re: bind to address while forwarding ports

From: Darren Tucker (dtucker_at_gate.dodgy.net.au)
Date: 03/06/05 

Date: 06 Mar 2005 04:10:54 GMT

On 2005-03-06, Andrew Tkachenko <pobugfix@peterlink.ru> wrote:
> I'm trying to forward requests to http server from boxA through boxB.
> Everything works fine, but I can't force sshd on boxB to bind to desired
> interface.
>
> on boxA I run ssh:
> ssh -N -L65005:google.com:80 user@boxB
>
> How can I force boxB to bind to some interace while forwarding to
> google.com:80 ?

I don't think the SSHv2 protocol spec even provides a way to specify the
address to bind to for a forwarded TCP connection.

Normally, the local address of an outbound TCP connection is decided at
connection intiation time by the host's routing table (ie whichever
interface the connection is routed out of becomes the source IP) so
perhaps you can make boxb do what you want via manipulating its routing
tables.

Alternatively you may be able to accomplish it with an external forwarder
(such as netcat) but I can't think of any way to do it without modifying
either ssh or netcat. 

-- 
Darren Tucker (dtucker at zip.com.au)
GPG key 8FF4FA69 / D9A3 86E9 7EEE AF4B B2D4  37C9 C982 80C7 8FF4 FA69
    Good judgement comes with experience. Unfortunately, the experience
usually comes from bad judgement.

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