Prob with remote port forwarding ( ssh -R)

Asked by stackdump

I'm using putty to connect to Ubuntu 7.04 w/ latest updates etc...
I'm trying to setup remote port forwarding (reverse tunneling), I have previously used Client to server forwarding.

from Putty's connection log
2007-08-09 16:09:53 Attempting to forward remote port to 127.0.0.1:4524
2007-08-09 16:09:53 Forwarded port opened successfully
2007-08-09 16:09:53 Forwarded port closed

from /var/log/auth.log:
 Aug 9 16:08:19 zim sshd[4900]: error: bind: Address already in use

from /etc/ssh/sshd_config
 #allow server to client forwarding
 GatewayPorts yes
 AllowTcpForwarding yes

For testing Im using netcat on the client machine with
 'nc -l -p 4524'

I'm able to connect to it locally w/ telnet to verify it is listenting.

the error in auth.log seems to show up as soon as the tunnel is configured
in putty i'm using
a Remote forwarding with 4524 and 127.0.0.1:4524 for the endpoints.
I do have the 'Remote port responds to other hosts' checked.

Also, Port 4524 doesn't show when I run nmap on the server... (I'm not sure if it is ever supposed to with Remote forwarding)

I've tried a variety of things using putty, I've been able to make client to server forwarding work fine. But never in reverse.
I Believe there is some network config issue on my Server, I just don't know what it is.

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stackdump (my-ork) said :
#1

*UPDATE*
I tried connecting using cygwin/openssh as the client, and this seems to work.
 I suppose the issue is a bug/config problem with putty.

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stackdump (my-ork) said :
#2

+ALSO+

Apparently the order that you setup the connections is important.

I had to start the listening port on my client computer before I added the remote tunnel.