How do I troubleshoot ssh tunnels disconnection?

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I am using SSH tunnels launched via autossh at boot on a device installed at remote locations. Up to now everything was working fine but yesterday the connection partly went down and autossh wouldn't do its thing. And I would love to figure out what happened to prevent it ever happening again. I have to deal with SLAs and all.



Here are the details:



THE SETUP



Remote site:



-Raspbian on a raspberry pi (debian wheezy)
-Autossh running at boot connects to our server and establishes 3 ssh tunnels
Tunnel 1: regular tunnel forwarding a local port on the raspberry pi to a server in our office
Tunnel 2: reverse tunnel opens a port on our server pointing to a device on the remote network
Tunnel 3: reverse tunnel opens a port from our server's loopback (127.0.0.1) adapter pointing to the ssh port of the raspberry pi on its loopback adapter.



So basically with this setup I have to ssh in our server from which I can ssh into each remote devices.



SSH Server:



-Debian Wheezy
-No firewall/iptables on the server, we use another box for this



THE PROBLEM



Both reverse tunnels (tunnels 2 and 3) stopped working. The output of



sudo netstat -atp | grep ssh


Showed that the only port still opened was for tunnel # 1



When I killed the ssh process on the server for tunnel # 1 autossh did its thing and all tunnels were reconnected but I would prefer if I didn't have to do this.



Is it normal behavior for autossh? Does autossh have issues monitoring reverse tunnels?



SYSLOG from the remote device



Sep 7 06:25:06 remote_hostname rsyslogd: [origin software="rsyslogd" swVersion="5.8.11" x-pid="1661" x-info="http://www.rsyslog.com"] rsyslogd was HUPed
Sep 8 06:25:05 remote_hostname rsyslogd: [origin software="rsyslogd" swVersion="5.8.11" x-pid="1661" x-info="http://www.rsyslog.com"] rsyslogd was HUPed
Sep 8 10:24:57 remote_hostname autossh[1428]: ssh exited with error status 255; restarting ssh
Sep 8 10:24:57 remote_hostname autossh[1428]: starting ssh (count 2)
Sep 8 10:24:57 remote_hostname autossh[1428]: ssh child pid is 24161
Sep 8 16:53:53 remote_hostname autossh[1428]: ssh exited with error status 255; restarting ssh
Sep 8 16:53:53 remote_hostname autossh[1428]: starting ssh (count 3)
Sep 8 16:53:53 remote_hostname autossh[1428]: ssh child pid is 30541
Sep 9 06:25:05 remote_hostname rsyslogd: [origin software="rsyslogd" swVersion="5.8.11" x-pid="1661" x-info="http://www.rsyslog.com"] rsyslogd was HUPed









share|improve this question



















  • 1





    Does it give more insight to run ssh with options -v, -vv, or -vvv?

    – Volker Siegel
    Sep 9 '14 at 15:39











  • Ha ha ha... I completely forgot that autossh is just a wrapper for ssh. I checked it's help dialog for debuging option and forgot to check ssh itself. Thank you!

    – TCZ8
    Sep 10 '14 at 12:43












  • So I'll make it an answer :)

    – Volker Siegel
    Sep 10 '14 at 12:45











  • Please do! My company just stopped supplying us with free coffee... I guess my ADD brain is having issues coping hehehe thanks again!

    – TCZ8
    Sep 10 '14 at 12:47












  • Ha, ask my brain...

    – Volker Siegel
    Sep 10 '14 at 12:50

















2















I am using SSH tunnels launched via autossh at boot on a device installed at remote locations. Up to now everything was working fine but yesterday the connection partly went down and autossh wouldn't do its thing. And I would love to figure out what happened to prevent it ever happening again. I have to deal with SLAs and all.



Here are the details:



THE SETUP



Remote site:



-Raspbian on a raspberry pi (debian wheezy)
-Autossh running at boot connects to our server and establishes 3 ssh tunnels
Tunnel 1: regular tunnel forwarding a local port on the raspberry pi to a server in our office
Tunnel 2: reverse tunnel opens a port on our server pointing to a device on the remote network
Tunnel 3: reverse tunnel opens a port from our server's loopback (127.0.0.1) adapter pointing to the ssh port of the raspberry pi on its loopback adapter.



So basically with this setup I have to ssh in our server from which I can ssh into each remote devices.



SSH Server:



-Debian Wheezy
-No firewall/iptables on the server, we use another box for this



THE PROBLEM



Both reverse tunnels (tunnels 2 and 3) stopped working. The output of



sudo netstat -atp | grep ssh


Showed that the only port still opened was for tunnel # 1



When I killed the ssh process on the server for tunnel # 1 autossh did its thing and all tunnels were reconnected but I would prefer if I didn't have to do this.



Is it normal behavior for autossh? Does autossh have issues monitoring reverse tunnels?



SYSLOG from the remote device



Sep 7 06:25:06 remote_hostname rsyslogd: [origin software="rsyslogd" swVersion="5.8.11" x-pid="1661" x-info="http://www.rsyslog.com"] rsyslogd was HUPed
Sep 8 06:25:05 remote_hostname rsyslogd: [origin software="rsyslogd" swVersion="5.8.11" x-pid="1661" x-info="http://www.rsyslog.com"] rsyslogd was HUPed
Sep 8 10:24:57 remote_hostname autossh[1428]: ssh exited with error status 255; restarting ssh
Sep 8 10:24:57 remote_hostname autossh[1428]: starting ssh (count 2)
Sep 8 10:24:57 remote_hostname autossh[1428]: ssh child pid is 24161
Sep 8 16:53:53 remote_hostname autossh[1428]: ssh exited with error status 255; restarting ssh
Sep 8 16:53:53 remote_hostname autossh[1428]: starting ssh (count 3)
Sep 8 16:53:53 remote_hostname autossh[1428]: ssh child pid is 30541
Sep 9 06:25:05 remote_hostname rsyslogd: [origin software="rsyslogd" swVersion="5.8.11" x-pid="1661" x-info="http://www.rsyslog.com"] rsyslogd was HUPed









share|improve this question



















  • 1





    Does it give more insight to run ssh with options -v, -vv, or -vvv?

    – Volker Siegel
    Sep 9 '14 at 15:39











  • Ha ha ha... I completely forgot that autossh is just a wrapper for ssh. I checked it's help dialog for debuging option and forgot to check ssh itself. Thank you!

    – TCZ8
    Sep 10 '14 at 12:43












  • So I'll make it an answer :)

    – Volker Siegel
    Sep 10 '14 at 12:45











  • Please do! My company just stopped supplying us with free coffee... I guess my ADD brain is having issues coping hehehe thanks again!

    – TCZ8
    Sep 10 '14 at 12:47












  • Ha, ask my brain...

    – Volker Siegel
    Sep 10 '14 at 12:50













2












2








2








I am using SSH tunnels launched via autossh at boot on a device installed at remote locations. Up to now everything was working fine but yesterday the connection partly went down and autossh wouldn't do its thing. And I would love to figure out what happened to prevent it ever happening again. I have to deal with SLAs and all.



Here are the details:



THE SETUP



Remote site:



-Raspbian on a raspberry pi (debian wheezy)
-Autossh running at boot connects to our server and establishes 3 ssh tunnels
Tunnel 1: regular tunnel forwarding a local port on the raspberry pi to a server in our office
Tunnel 2: reverse tunnel opens a port on our server pointing to a device on the remote network
Tunnel 3: reverse tunnel opens a port from our server's loopback (127.0.0.1) adapter pointing to the ssh port of the raspberry pi on its loopback adapter.



So basically with this setup I have to ssh in our server from which I can ssh into each remote devices.



SSH Server:



-Debian Wheezy
-No firewall/iptables on the server, we use another box for this



THE PROBLEM



Both reverse tunnels (tunnels 2 and 3) stopped working. The output of



sudo netstat -atp | grep ssh


Showed that the only port still opened was for tunnel # 1



When I killed the ssh process on the server for tunnel # 1 autossh did its thing and all tunnels were reconnected but I would prefer if I didn't have to do this.



Is it normal behavior for autossh? Does autossh have issues monitoring reverse tunnels?



SYSLOG from the remote device



Sep 7 06:25:06 remote_hostname rsyslogd: [origin software="rsyslogd" swVersion="5.8.11" x-pid="1661" x-info="http://www.rsyslog.com"] rsyslogd was HUPed
Sep 8 06:25:05 remote_hostname rsyslogd: [origin software="rsyslogd" swVersion="5.8.11" x-pid="1661" x-info="http://www.rsyslog.com"] rsyslogd was HUPed
Sep 8 10:24:57 remote_hostname autossh[1428]: ssh exited with error status 255; restarting ssh
Sep 8 10:24:57 remote_hostname autossh[1428]: starting ssh (count 2)
Sep 8 10:24:57 remote_hostname autossh[1428]: ssh child pid is 24161
Sep 8 16:53:53 remote_hostname autossh[1428]: ssh exited with error status 255; restarting ssh
Sep 8 16:53:53 remote_hostname autossh[1428]: starting ssh (count 3)
Sep 8 16:53:53 remote_hostname autossh[1428]: ssh child pid is 30541
Sep 9 06:25:05 remote_hostname rsyslogd: [origin software="rsyslogd" swVersion="5.8.11" x-pid="1661" x-info="http://www.rsyslog.com"] rsyslogd was HUPed









share|improve this question
















I am using SSH tunnels launched via autossh at boot on a device installed at remote locations. Up to now everything was working fine but yesterday the connection partly went down and autossh wouldn't do its thing. And I would love to figure out what happened to prevent it ever happening again. I have to deal with SLAs and all.



Here are the details:



THE SETUP



Remote site:



-Raspbian on a raspberry pi (debian wheezy)
-Autossh running at boot connects to our server and establishes 3 ssh tunnels
Tunnel 1: regular tunnel forwarding a local port on the raspberry pi to a server in our office
Tunnel 2: reverse tunnel opens a port on our server pointing to a device on the remote network
Tunnel 3: reverse tunnel opens a port from our server's loopback (127.0.0.1) adapter pointing to the ssh port of the raspberry pi on its loopback adapter.



So basically with this setup I have to ssh in our server from which I can ssh into each remote devices.



SSH Server:



-Debian Wheezy
-No firewall/iptables on the server, we use another box for this



THE PROBLEM



Both reverse tunnels (tunnels 2 and 3) stopped working. The output of



sudo netstat -atp | grep ssh


Showed that the only port still opened was for tunnel # 1



When I killed the ssh process on the server for tunnel # 1 autossh did its thing and all tunnels were reconnected but I would prefer if I didn't have to do this.



Is it normal behavior for autossh? Does autossh have issues monitoring reverse tunnels?



SYSLOG from the remote device



Sep 7 06:25:06 remote_hostname rsyslogd: [origin software="rsyslogd" swVersion="5.8.11" x-pid="1661" x-info="http://www.rsyslog.com"] rsyslogd was HUPed
Sep 8 06:25:05 remote_hostname rsyslogd: [origin software="rsyslogd" swVersion="5.8.11" x-pid="1661" x-info="http://www.rsyslog.com"] rsyslogd was HUPed
Sep 8 10:24:57 remote_hostname autossh[1428]: ssh exited with error status 255; restarting ssh
Sep 8 10:24:57 remote_hostname autossh[1428]: starting ssh (count 2)
Sep 8 10:24:57 remote_hostname autossh[1428]: ssh child pid is 24161
Sep 8 16:53:53 remote_hostname autossh[1428]: ssh exited with error status 255; restarting ssh
Sep 8 16:53:53 remote_hostname autossh[1428]: starting ssh (count 3)
Sep 8 16:53:53 remote_hostname autossh[1428]: ssh child pid is 30541
Sep 9 06:25:05 remote_hostname rsyslogd: [origin software="rsyslogd" swVersion="5.8.11" x-pid="1661" x-info="http://www.rsyslog.com"] rsyslogd was HUPed






ssh ssh-tunneling sshd syslog troubleshooting






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share|improve this question













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edited Mar 10 at 4:34









Rui F Ribeiro

42k1483142




42k1483142










asked Sep 9 '14 at 15:03









TCZ8TCZ8

5443820




5443820







  • 1





    Does it give more insight to run ssh with options -v, -vv, or -vvv?

    – Volker Siegel
    Sep 9 '14 at 15:39











  • Ha ha ha... I completely forgot that autossh is just a wrapper for ssh. I checked it's help dialog for debuging option and forgot to check ssh itself. Thank you!

    – TCZ8
    Sep 10 '14 at 12:43












  • So I'll make it an answer :)

    – Volker Siegel
    Sep 10 '14 at 12:45











  • Please do! My company just stopped supplying us with free coffee... I guess my ADD brain is having issues coping hehehe thanks again!

    – TCZ8
    Sep 10 '14 at 12:47












  • Ha, ask my brain...

    – Volker Siegel
    Sep 10 '14 at 12:50












  • 1





    Does it give more insight to run ssh with options -v, -vv, or -vvv?

    – Volker Siegel
    Sep 9 '14 at 15:39











  • Ha ha ha... I completely forgot that autossh is just a wrapper for ssh. I checked it's help dialog for debuging option and forgot to check ssh itself. Thank you!

    – TCZ8
    Sep 10 '14 at 12:43












  • So I'll make it an answer :)

    – Volker Siegel
    Sep 10 '14 at 12:45











  • Please do! My company just stopped supplying us with free coffee... I guess my ADD brain is having issues coping hehehe thanks again!

    – TCZ8
    Sep 10 '14 at 12:47












  • Ha, ask my brain...

    – Volker Siegel
    Sep 10 '14 at 12:50







1




1





Does it give more insight to run ssh with options -v, -vv, or -vvv?

– Volker Siegel
Sep 9 '14 at 15:39





Does it give more insight to run ssh with options -v, -vv, or -vvv?

– Volker Siegel
Sep 9 '14 at 15:39













Ha ha ha... I completely forgot that autossh is just a wrapper for ssh. I checked it's help dialog for debuging option and forgot to check ssh itself. Thank you!

– TCZ8
Sep 10 '14 at 12:43






Ha ha ha... I completely forgot that autossh is just a wrapper for ssh. I checked it's help dialog for debuging option and forgot to check ssh itself. Thank you!

– TCZ8
Sep 10 '14 at 12:43














So I'll make it an answer :)

– Volker Siegel
Sep 10 '14 at 12:45





So I'll make it an answer :)

– Volker Siegel
Sep 10 '14 at 12:45













Please do! My company just stopped supplying us with free coffee... I guess my ADD brain is having issues coping hehehe thanks again!

– TCZ8
Sep 10 '14 at 12:47






Please do! My company just stopped supplying us with free coffee... I guess my ADD brain is having issues coping hehehe thanks again!

– TCZ8
Sep 10 '14 at 12:47














Ha, ask my brain...

– Volker Siegel
Sep 10 '14 at 12:50





Ha, ask my brain...

– Volker Siegel
Sep 10 '14 at 12:50










1 Answer
1






active

oldest

votes


















1














You are using various ways to create log output,

but do not mention the most important ones:



The command ssh itself has a "verbose" option -v.

And more interesting, it also has a "verry verbose" option -vv.

Oh, and "verry verry verbose", -vvv, which may actually be too verbose!



Does it give more insight to run ssh with options -v, -vv, or -vvv?



Showing how much verbosity the options enable:



$ ssh -v localhost true |& wc -l 
56
$ ssh -vv localhost true |& wc -l
122
$ ssh -vvv localhost true |& wc -l
282





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    1 Answer
    1






    active

    oldest

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    active

    oldest

    votes






    active

    oldest

    votes









    1














    You are using various ways to create log output,

    but do not mention the most important ones:



    The command ssh itself has a "verbose" option -v.

    And more interesting, it also has a "verry verbose" option -vv.

    Oh, and "verry verry verbose", -vvv, which may actually be too verbose!



    Does it give more insight to run ssh with options -v, -vv, or -vvv?



    Showing how much verbosity the options enable:



    $ ssh -v localhost true |& wc -l 
    56
    $ ssh -vv localhost true |& wc -l
    122
    $ ssh -vvv localhost true |& wc -l
    282





    share|improve this answer





























      1














      You are using various ways to create log output,

      but do not mention the most important ones:



      The command ssh itself has a "verbose" option -v.

      And more interesting, it also has a "verry verbose" option -vv.

      Oh, and "verry verry verbose", -vvv, which may actually be too verbose!



      Does it give more insight to run ssh with options -v, -vv, or -vvv?



      Showing how much verbosity the options enable:



      $ ssh -v localhost true |& wc -l 
      56
      $ ssh -vv localhost true |& wc -l
      122
      $ ssh -vvv localhost true |& wc -l
      282





      share|improve this answer



























        1












        1








        1







        You are using various ways to create log output,

        but do not mention the most important ones:



        The command ssh itself has a "verbose" option -v.

        And more interesting, it also has a "verry verbose" option -vv.

        Oh, and "verry verry verbose", -vvv, which may actually be too verbose!



        Does it give more insight to run ssh with options -v, -vv, or -vvv?



        Showing how much verbosity the options enable:



        $ ssh -v localhost true |& wc -l 
        56
        $ ssh -vv localhost true |& wc -l
        122
        $ ssh -vvv localhost true |& wc -l
        282





        share|improve this answer















        You are using various ways to create log output,

        but do not mention the most important ones:



        The command ssh itself has a "verbose" option -v.

        And more interesting, it also has a "verry verbose" option -vv.

        Oh, and "verry verry verbose", -vvv, which may actually be too verbose!



        Does it give more insight to run ssh with options -v, -vv, or -vvv?



        Showing how much verbosity the options enable:



        $ ssh -v localhost true |& wc -l 
        56
        $ ssh -vv localhost true |& wc -l
        122
        $ ssh -vvv localhost true |& wc -l
        282






        share|improve this answer














        share|improve this answer



        share|improve this answer








        edited Sep 15 '14 at 1:01

























        answered Sep 10 '14 at 12:49









        Volker SiegelVolker Siegel

        11.1k33361




        11.1k33361



























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