Unable to open SSH tunnel.

Discussion of Co:Z sftp, a port of OpenSSH sftp for z/OS
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ebbie
Posts: 18
Joined: Tue Feb 16, 2010 8:52 am

Unable to open SSH tunnel.

Post by ebbie »

Hi

I have FTPSSHPROXY working across most of my systems. However on one system i cannot get it going. Below is the log output of a job that failed.

2011-11-23 11:44:13,658 INFO FtpControlSession./XXX.XX.XX.XX:2080 - client login accepted for userid "xxxxxxx"
2011-11-23 11:44:16,522 WARN FtpControlSession./XXX.XX.XX.XX:2080. - Exception starting SSH tunnel
com.jcraft.jsch.JSchException: channel is not opened.
.at com.jcraft.jsch.ChannelDirectTCPIP.connect(ChannelDirectTCPIP.java:105)
.at com.dovetail.ftpsshproxy.FtpControlSession.startSshTunnel(FtpControlSession.java:241)
.at com.dovetail.ftpsshproxy.FtpControlSession.startConnection(FtpControlSession.java:129)
.at com.dovetail.ftpsshproxy.FtpControlSession.run(FtpControlSession.java:76)
.at com.dovetail.ftpsshproxy.ProxyConnection.runProxySession(ProxyConnection.java:135)
.at com.dovetail.ftpsshproxy.ProxyConnection.doRun(ProxyConnection.java:91)
.at com.dovetail.ftpsshproxy.ProxyConnection.run(ProxyConnection.java:72)
.at java.lang.Thread.run(Thread.java:811)
2011-11-23 11:44:16,523 DEBUG FtpControlSession./XXX.XX.XX.XX:2080. - C< 530 channel is not opened.

Any suggestions.
dovetail
Site Admin
Posts: 2025
Joined: Thu Jul 29, 2004 12:12 pm

Re: Unable to open SSH tunnel.

Post by dovetail »

My best guess is that the target SSHD server does not allow port forwarding. Check the logs for the sshd server to confirm.
cmcgavic
Posts: 14
Joined: Wed Jul 07, 2010 1:55 pm
Location: Louisville, Ky

Re: Unable to open SSH tunnel.

Post by cmcgavic »

I too am getting the same thing:

2012-03-06 16:10:31,292 INFO ProxyConnection./127.0.0.1:1534. - proxy negotiated to /192.168.164.75:21
2012-03-06 16:10:31,374 INFO FtpControlSession./127.0.0.1:1534. - client login accepted for userid "azs003
2012-03-06 16:10:36,282 WARN FtpControlSession./127.0.0.1:1534. - Exception starting SSH tunnel
com.jcraft.jsch.JSchException: channel is not opened.
.at com.jcraft.jsch.ChannelDirectTCPIP.connect(ChannelDirectTCPIP.java:105)
.at com.dovetail.ftpsshproxy.FtpControlSession.startSshTunnel(FtpControlSession.java:241)
.at com.dovetail.ftpsshproxy.FtpControlSession.startConnection(FtpControlSession.java:129)
.at com.dovetail.ftpsshproxy.FtpControlSession.run(FtpControlSession.java:76)
.at com.dovetail.ftpsshproxy.ProxyConnection.runProxySession(ProxyConnection.java:135)
.at com.dovetail.ftpsshproxy.ProxyConnection.doRun(ProxyConnection.java:91)
.at com.dovetail.ftpsshproxy.ProxyConnection.run(ProxyConnection.java:72)
.at java.lang.Thread.run(Thread.java:737)
2012-03-06 16:10:36,298 INFO FtpControlSession./127.0.0.1:1534. - disconnected SSH
2012-03-06 16:10:36,303 INFO ProxyConnection./127.0.0.1:1534. - control connection closed

It occurs when I go to my fairly new z/OS 1.12 system, but not the 1.10 systems. The SSHD config is the same as it always has been.

On the /tmp/syslog.log I have:

Mar 6 16:10:34 ARCTECHLPAR sshdÝ33554478¨: Port of Entry information retained for uid:0 pid:33554478.
Mar 6 16:10:36 ARCTECHLPAR sshdÝ33554478¨: Accepted password for azs003 from 192.168.164.73 port 1535 ssh2
Mar 6 16:10:36 ARCTECHLPAR sshdÝ33554478¨: Received request to connect to host localhost port 21, but the request was denied.

Any insight is appreciated.
cmcgavic
Posts: 14
Joined: Wed Jul 07, 2010 1:55 pm
Location: Louisville, Ky

Re: Unable to open SSH tunnel.

Post by cmcgavic »

The problem is on my z/OS 1.12 system that isn't quite right. I brought z/OS 1.10 back up on my sandbox and it worked. Now to start looking for the needle in a hay stack. I'll report back when I find it.
cmcgavic
Posts: 14
Joined: Wed Jul 07, 2010 1:55 pm
Location: Louisville, Ky

Re: Unable to open SSH tunnel.

Post by cmcgavic »

I see nothing different between my 1.10 and 1.12 z/os configs that would cause port 21 to refuse the connection from 1.10.

Help please.
cmcgavic
Posts: 14
Joined: Wed Jul 07, 2010 1:55 pm
Location: Louisville, Ky

Re: Unable to open SSH tunnel.

Post by cmcgavic »

Well, looks like the default for AllowTcpForwarding changed from yes to no when going to Ported Tools OPENSSH 1.2.
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