intermittent ssh port 22 connection refused problem

Paul Allen Newell
Sun Aug 12 23:09:00 GMT 2012


I have a WinXP with cygwin and a couple Fedora 16 boxes on my LAN. Every 
once in a awhile, I am unable to ssh/scp/telnet from the Fedora boxes to 
the cygwin box (port 22 connection refused). I've never been able to get 
a reproducible case and it usually corrects itself the next time I power 
up everything.

The WinXP can ssh/scp to the Fedora boxes and the Fedora boxes can all 
ssh/scp to each other.

It happened yesterday and I could not get it to start working no matter 
how many reboots I did on both machines. I gave up for the night before 
I did something stupid, came back today, and it is all working. The only 
"weak clue" I have is that I remember twice not being able to do it and 
noticing that I hadn't open a cygwin shell on the WinXP box. Shouldn't 
make any difference as when it is working, it doesn't matter whether I 
have a cygwin shell open. (right?)

I was able to confirm that the problem is most likely on cygwin side 
(not positive, but likely) as a self-referring ssh into myself on cygwin 

I can trap an error message from iptables on the Fedora side (yoyo is 
the F16 box, is the WinXP cygwin box):
Aug 11 23:43:43 yoyo kernel: [ 779.725071] <IPTABLES: LOG REJECT> 
IN=eth0 OUT= MAC=ff:ff:ff:ff:ff:ff:00:1e:8c:c3:21:d6:08:00 
SRC= DST= LEN=229 TOS=0x00 PREC=0x00 TTL=128 
ID=33554 PROTO=UDP SPT=138 DPT=138 LEN=209
Aug 11 23:43:48 yoyo kernel: [ 785.386501] <IPTABLES: LOG REJECT> 
IN=eth0 OUT= MAC=ff:ff:ff:ff:ff:ff:00:1e:8c:c3:21:d6:08:00 
SRC= DST= LEN=234 TOS=0x00 PREC=0x00 TTL=128 
ID=33555 PROTO=UDP SPT=138 DPT=138 LEN=214

I have no idea how to get any log messages on the cygwin side (google 
searches indicate that iptables in not available on cygwin/windows). I 
did a google on "cygwin ssh intermittent" and saw reported problems, but 
none seemed the same (the closest was a "Connection timed out" but I 
couldn't find a trail for replies to it).

Any suggestions about how to try to figure it out? (based on the 
assumption that I am not able to repeat the failure and I may have to 
wait until it decides to show itself again)

Thanks in advance,
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