Ssh hangs after authentication

From: Adam Kerrison (Adam.Kerrison_at_tideway.com)
Date: 08/24/05

  • Next message: Bob Rasmussen: "Re: Password Ageing" 
    Date: Wed, 24 Aug 2005 09:16:50 +0100
To: <secureshell@securityfocus.com>

    Hi

    I'm having trouble with openssh when connecting from my Mac OS X (Tiger)
    laptop at home to a Linux server in my office. When I'm in the office
    everything works fine, when I'm at home the ssh connection just hangs.
    I have an ADSL router at home which acts as a Firewall with NAT but I don't
    believe the problem is there (see below). Also from home I have to use a
    CiscoVPN but again I don't think that's the problem.

    When I connect via ssh it hangs right after the authentication has succeed
    and just before I would expect the shell prompt. Running ssh -vvv shows all
    the authentication steps and ends with:

    debug1: Authentication succeeded (publickey).
    debug1: channel 0: new [client-session]
    debug3: ssh_session2_open: channel_new: 0
    debug2: channel 0: send open
    debug1: Entering interactive session.
    debug2: callback start
    debug2: ssh_session2_setup: id 0
    debug2: channel 0: request pty-req
    debug3: tty_make_modes: ospeed 9600
    debug3: tty_make_modes: ispeed 9600
    debug3: tty_make_modes: < ... Lots of theses, snipped ... >
    debug2: channel 0: request shell
    debug2: fd 3 setting TCP_NODELAY
    debug2: callback done
    debug2: channel 0: open confirm rwindow 0 rmax 32768

    At this point its dead. I have to kill the local ssh client or remote sshd.
    I ran up an sshd in debug mode to try and find out what's happening but
    there's nothing in the logs that would indicate a problem.

    Now the final twist: If I use PuTTY from a Windows machine at home it works
    fine. I have now downloaded and tried the Mac OS X version of PuTTY and that
    also works!

    Searching back through the mail list archives I've seen several other people
    reporting the same or similar issue but no resolutions - does anyone know
    what's going on here because I'm really stumped! I have saved all the logs
    if anyone wants to dig deeper (they are large so I didn't want to include
    them) and I can run up test daemons etc.

    Sorry for the long post ...

    Adam K

  • Next message: Bob Rasmussen: "Re: Password Ageing"

    Relevant Pages

    • X11 Forwarding problems without an interactive shell
      ... I saw a mention that using -x +x command switches with ssh ... In the successful case I notice there is a request of a shell ... debug2: channel 0: request pty-req confirm 0 ...
      (comp.os.vms)
    • Re: Permission denied (publickey,keyboard-interactive).
      ... Ssh freeze... ... debug2: fd 5 setting O_NONBLOCK ... debug3: fd 6 is O_NONBLOCK ... debug1: channel 0: new ...
      (comp.security.ssh)
    • Re: Can not start xlogo
      ... ssh -Xvvv root@xxxxxxxxxxx 'echo $DISPLAY' ... ssh -Xvvv root@xxxxxxxxxxx 'echo aaa $DISPLAY aaa"' ... debug2: we sent a password packet, ... debug2: channel 0: request exec confirm 0 ...
      (comp.unix.admin)
    • Tiger SSH local net failure
      ... can't login to the mysql server because ssh wont connect to the G4. ... stuck because I can no longer ssh from any macs to internal machines mac or ... debug1: Connection established. ... debug2: fd 3 setting O_NONBLOCK ...
      (SSH)
    • ssh hang with a CTRL-D before prompt on solaris 2.6
      ... I use ssh to log around at my job ... debug1: read PEM private key done: type DSA ... debug1: channel 0: new ... debug2: tty_make_modes: ospeed 38400 ...
      (comp.security.ssh)