Mailing List Archive: TCP connection forwarding troubles

TCP connection forwarding troubles

Jun 13, 2000, 5:17 PM

Post #1 of 3 (869 views)

For some time I have routinely websurfed across a forwarded TCP
connection using SSH. The other end of the TCP tunnel connects to a
Squid proxy cache on the same machine.

This usually works. But I see lots of error messages on each end of
the form

Jun 13 13:22:02 tunnel sshd[32378]: error: channel 0: chan_shutdown_read: shutdown() failed for fd5 [i1 o128]: Transport endpoint is not connected
Jun 13 13:22:11 tunnel sshd[32378]: error: channel 2: chan_shutdown_read: shutdown() failed for fd10 [i1 o128]: Transport endpoint is not connected
Jun 13 13:24:50 tunnel sshd[32378]: error: channel 0: chan_shutdown_read: shutdown() failed for fd5 [i1 o128]: Transport endpoint is not connected
Jun 13 13:25:03 tunnel sshd[32378]: error: channel 1: chan_shutdown_read: shutdown() failed for fd8 [i1 o128]: Transport endpoint is not connected
Jun 13 13:25:03 tunnel sshd[32378]: error: channel 3: chan_shutdown_read: shutdown() failed for fd11 [i1 o128]: Transport endpoint is not connected
Jun 13 13:25:03 tunnel sshd[32378]: error: channel 2: chan_shutdown_read: shutdown() failed for fd10 [i1 o128]: Transport endpoint is not connected
Jun 13 13:25:14 tunnel sshd[32378]: error: channel 5: chan_shutdown_read: shutdown() failed for fd13 [i1 o128]: Transport endpoint is not connected
Jun 13 13:46:02 tunnel sshd[32378]: error: channel 3: chan_shutdown_read: shutdown() failed for fd11 [i1 o128]: Transport endpoint is not connected

This is from the remote end of the tunnel, the machine with the squid
proxy. I see similar messages on the client side.

And occasionally things often just hang. When I kill and restart the
local ssh client that's providing the tunnel, it starts working again.

Both ends are running OpenSSH 2.1.1, Debian Linux 2.1 and the 2.2.15 kernel.

--Phil

Re: TCP connection forwarding troubles [ In reply to ]

P.S.S.Camp at ukc

Jun 14, 2000, 12:33 AM

Post #2 of 3 (831 views)

Permalink

On Tue, 13 Jun 2000, Phil Karn wrote:

> For some time I have routinely websurfed across a forwarded TCP
> connection using SSH. The other end of the TCP tunnel connects to a
> Squid proxy cache on the same machine.
>
> This usually works. But I see lots of error messages on each end of
> the form
>
> Jun 13 13:22:02 tunnel sshd[32378]: error: channel 0: chan_shutdown_read: shutdown() failed for fd5 [i1 o128]: Transport endpoint is not connected
> Jun 13 13:22:11 tunnel sshd[32378]: error: channel 2: chan_shutdown_read: shutdown() failed for fd10 [i1 o128]: Transport endpoint is not connected
> Jun 13 13:24:50 tunnel sshd[32378]: error: channel 0: chan_shutdown_read: shutdown() failed for fd5 [i1 o128]: Transport endpoint is not connected
> Jun 13 13:25:03 tunnel sshd[32378]: error: channel 1: chan_shutdown_read: shutdown() failed for fd8 [i1 o128]: Transport endpoint is not connected
> Jun 13 13:25:03 tunnel sshd[32378]: error: channel 3: chan_shutdown_read: shutdown() failed for fd11 [i1 o128]: Transport endpoint is not connected
> Jun 13 13:25:03 tunnel sshd[32378]: error: channel 2: chan_shutdown_read: shutdown() failed for fd10 [i1 o128]: Transport endpoint is not connected
> Jun 13 13:25:14 tunnel sshd[32378]: error: channel 5: chan_shutdown_read: shutdown() failed for fd13 [i1 o128]: Transport endpoint is not connected
> Jun 13 13:46:02 tunnel sshd[32378]: error: channel 3: chan_shutdown_read: shutdown() failed for fd11 [i1 o128]: Transport endpoint is not connected
>
> This is from the remote end of the tunnel, the machine with the squid
> proxy. I see similar messages on the client side.
>
> And occasionally things often just hang. When I kill and restart the
> local ssh client that's providing the tunnel, it starts working again.
>
get this when killing any proxyed conecttion (inc X) under solaris too.

Phill.

--
Computer Science Computing Officer

Re: TCP connection forwarding troubles [ In reply to ]

markus.friedl at informatik

Jun 15, 2000, 5:59 AM

Post #3 of 3 (836 views)

Permalink

Does this happen for protocol 1 or 2?
could you please send a 'ssh -v' trace?

On Tue, Jun 13, 2000 at 06:17:06PM -0700, Phil Karn wrote:
> For some time I have routinely websurfed across a forwarded TCP
> connection using SSH. The other end of the TCP tunnel connects to a
> Squid proxy cache on the same machine.
>
> This usually works. But I see lots of error messages on each end of
> the form
>
> Jun 13 13:22:02 tunnel sshd[32378]: error: channel 0: chan_shutdown_read: shutdown() failed for fd5 [i1 o128]: Transport endpoint is not connected
> Jun 13 13:22:11 tunnel sshd[32378]: error: channel 2: chan_shutdown_read: shutdown() failed for fd10 [i1 o128]: Transport endpoint is not connected
> Jun 13 13:24:50 tunnel sshd[32378]: error: channel 0: chan_shutdown_read: shutdown() failed for fd5 [i1 o128]: Transport endpoint is not connected
> Jun 13 13:25:03 tunnel sshd[32378]: error: channel 1: chan_shutdown_read: shutdown() failed for fd8 [i1 o128]: Transport endpoint is not connected
> Jun 13 13:25:03 tunnel sshd[32378]: error: channel 3: chan_shutdown_read: shutdown() failed for fd11 [i1 o128]: Transport endpoint is not connected
> Jun 13 13:25:03 tunnel sshd[32378]: error: channel 2: chan_shutdown_read: shutdown() failed for fd10 [i1 o128]: Transport endpoint is not connected
> Jun 13 13:25:14 tunnel sshd[32378]: error: channel 5: chan_shutdown_read: shutdown() failed for fd13 [i1 o128]: Transport endpoint is not connected
> Jun 13 13:46:02 tunnel sshd[32378]: error: channel 3: chan_shutdown_read: shutdown() failed for fd11 [i1 o128]: Transport endpoint is not connected
>
> This is from the remote end of the tunnel, the machine with the squid
> proxy. I see similar messages on the client side.
>
> And occasionally things often just hang. When I kill and restart the
> local ssh client that's providing the tunnel, it starts working again.
>
> Both ends are running OpenSSH 2.1.1, Debian Linux 2.1 and the 2.2.15 kernel.
>
> --Phil
>