Hi Rick, On 23/01/07, Rick Sewill <rsewill@xxxxxxxxxxxx> wrote:
When you ssh from machine A to machine B, can you ssh from machine B to machine C?
Yes, I can.
It may not provide much information, but my next instinct would be to turn on verbose mode, "man ssh" ssh -v -v -v -p 8888 localhost
ssh -vvv -p 8888 localhost OpenSSH_4.3p2, OpenSSL 0.9.8b 04 May 2006 debug1: Reading configuration data /etc/ssh/ssh_config debug1: Applying options for * debug2: ssh_connect: needpriv 0 debug1: Connecting to localhost [::1] port 8888. debug1: Connection established. debug1: identity file /home/jgu/.ssh/identity type -1 debug1: identity file /home/jgu/.ssh/id_rsa type -1 debug1: identity file /home/jgu/.ssh/id_dsa type -1 ssh_exchange_identification: Connection closed by remote host and, also, if I start up the tunnel with -vvv, I get this each time I try to connect to port 8888 on the local host: debug1: Connection to port 8888 forwarding to withnail.phys.ucl.ac.uk port 22 requested. debug2: fd 9 setting TCP_NODELAY debug2: fd 9 setting O_NONBLOCK debug3: fd 9 is O_NONBLOCK debug1: channel 3: new [direct-tcpip] channel 3: open failed: administratively prohibited: open failed debug1: channel 3: free: direct-tcpip: listening port 8888 for withnail.phys.ucl.ac.uk port 22, connect from ::1 port 36180, nchannels 4 debug3: channel 3: status: The following connections are open: #2 client-session (t4 r0 i0/0 o0/0 fd 6/7 cfd -1) #3 direct-tcpip: listening port 8888 for withnail.phys.ucl.ac.uk port 22, connect from ::1 port 36180 (t3 r-1 i0/0 o0/0 fd 9/9 cfd -1) debug3: channel 3: close_fds r 9 w 9 e -1 c -1 debug1: Connection to port 8888 forwarding to withnail.phys.ucl.ac.uk port 22 requested. debug2: fd 9 setting TCP_NODELAY debug2: fd 9 setting O_NONBLOCK debug3: fd 9 is O_NONBLOCK debug1: channel 3: new [direct-tcpip] channel 3: open failed: administratively prohibited: open failed debug1: channel 3: free: direct-tcpip: listening port 8888 for withnail.phys.ucl.ac.uk port 22, connect from ::1 port 36181, nchannels 4 debug3: channel 3: status: The following connections are open: #2 client-session (t4 r0 i0/0 o0/0 fd 6/7 cfd -1) #3 direct-tcpip: listening port 8888 for withnail.phys.ucl.ac.uk port 22, connect from ::1 port 36181 (t3 r-1 i0/0 o0/0 fd 9/9 cfd -1) debug3: channel 3: close_fds r 9 w 9 e -1 c -1 Does that shed any light ? J.