ssh/sshd hang after "debug2: channel 0: open confirm rwindow 0 rmax 32768"
Bruce Allen
ballen at gravity.phys.uwm.edu
Sat Mar 15 21:27:09 EST 2008
Dear openssh developers,
Sorry to bother you with this, but I am stumped!
ssh client version:
OpenSSH_3.9p1 NCSA_GSSAPI_3.5 GSI, OpenSSL 0.9.7d 17 Mar 2004
sshd server version:
OpenSSH_4.6p1-hpn12v17 NCSA_GSSAPI_GPT_4.0 GSI, OpenSSL 0.9.7d 17 Mar 2004
The client/server interaction hangs just at the very end, after
authentication is complete. Here are a few lines of ssh -v -v -v output:
------------------------------------------------------------
...
debug3: tty_make_modes: 90 1
debug3: tty_make_modes: 91 1
debug3: tty_make_modes: 92 0
debug3: tty_make_modes: 93 0
debug2: channel 0: request shell confirm 0
debug2: fd 3 setting TCP_NODELAY
debug2: callback done
debug2: channel 0: open confirm rwindow 0 rmax 32768
[HANGS HERE FOR A COUPLE OF MINUTES! Then after an agonizing wait...]
debug1: channel 0: free: client-session, nchannels 1
debug3: channel 0: status: The following connections are open:
#0 client-session (t4 r0 i0/0 o0/0 fd 5/7 cfd -1)
debug3: channel 0: close_fds r 5 w 7 e 8 c -1
Read from remote host XXX.XXX.uwm.edu: Operation timed out
------------------------------------------------------------
This bug has appeared on a stable set of systems that have worked well for
quite some time. The only thing that has changed is that I am in a hotel
room with some new ISP (in a few hours I'll try from a different
location). We have a number of hosts set up the same way, and I can not
log into any of them, so it's probably not machine misconfiguration on the
server side. And the client works fine with a different set of hosts!
So it's probably not machine misconfiguration on the client side either.
Only thing I have checked is that I've dropped my MTU to 576 thinking that
there might be some packet fragmentation issues with the hotel's NAT box
but that didn't help.
PS: Thanks for openssh. We wouldn't be able to work without it!
Cheers,
Bruce Allen
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