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Old 10-12-2007, 01:23 AM   #1
amadkow
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ssh over high latency connections


I am trying to connect to my ssh server over a very high latency connection. I am guessing the connection is timing out when I try to connect. When I connect from a low latency connection I have no problems. Any ideas on what settings I can change on the ssh server to work with high latency connections?
 
Old 10-12-2007, 01:33 AM   #2
acid_kewpie
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well you'd need a pretty astonishing latency to see somethign that dramatic... are you actually connecting at all? run "tcpdump port 22 -n" to see the ssh activity on the system, see if packets actually are coming back, and what's happening around the time of a timeout...
 
Old 10-12-2007, 01:44 AM   #3
amadkow
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The connection here is very bad but I can't really do anything about that. I am most likely looking at where from 600ms to 1000ms or higher.

It looks like when I try to connect it goes something like this

from me to ssh syn
from ssh to me rst, ack
from me to ssh syn
from me to ssh syn

thats all the traffic i am seeing when I try to connect using ssh.
 
Old 10-12-2007, 02:05 AM   #4
acid_kewpie
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ok, well the full output would be more useful, but the server has reset you... that's an explicit refusal from the server, *OR* something inbetween spoofing a server packet, like a firewall, IDS or something.
 
Old 10-12-2007, 03:15 AM   #5
amadkow
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I can't post the full output. I am pretty sure out firewall doesn't block ssh traffic and I have our firewall guys double checking that for me. I know the server is not set up to block any one from connecting to ssh on it.
 
Old 10-12-2007, 03:18 AM   #6
acid_kewpie
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well a RST is an RST... there are only so many ways you can interpret it... that's the joy of packet sniffing, unequivocal proof at a low level.
 
Old 10-12-2007, 04:09 AM   #7
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I figured it out there was another firewall not many people knew about here. Thanks for the help.
 
Old 10-12-2007, 05:39 AM   #8
rmitev
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when you have big response times - what is server loadaverage ?
it is possible to have big response times when your server is heavy loaded ...

try to ping your host ... do you have similar timeouts or there is a big difference (for ex. 50 - 2000 msec)
 
Old 10-12-2007, 05:49 AM   #9
acid_kewpie
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he's already confirmed it was a firewall issue...
 
Old 10-12-2007, 06:37 AM   #10
rmitev
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sorry i have not read #7 post
 
  


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