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RE: Newbie ssh question
- From: "James Hall" <james dot c dot hall at ntlworld dot com>
- To: "Jeff Mincy" <jeff at delphioutpost dot com>,"Adrian Phillips" <adrianp at powertech dot no>
- Cc: <cygwin at cygwin dot com>
- Date: Mon, 7 Jan 2002 15:58:23 -0000
- Subject: RE: Newbie ssh question
Thanks for responding to my original question.
Although not strictly correct you pointed me in the right direction. For any
one else with this problem:
In order to use TCP keep alive on W2K the appropriate registry entries are:-
Values: KeepAliveTime and KeepAliveInterval
The M$ documentation on these is both somewhat vague and misleading. The
second value is the interval between keep-alive packets to be sent when no
reply has been received from the remote host (the number sent before giving
up being determined by the MaxDataRetries value) - the suggested value of
1000 (1000ms = 1s) is sensible. The first value is the time to wait before
sending a keep-alive message - the suggested value of 7200000 (=2hrs) is
nonsensical if intervening firewalls are detecting and blocking quiescent
connections. A value of 1s is more appropriate and is well on the safe side.
By default neither of these values is included in the registry. I have added
them, observed using TCPdump that they now cause keep-alives to be sent, and
all is now well.
Incidentally, the W98 etc registry key
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\VxD\MSTCP is also
present in the W2K registry - I have also added the above values to this
key, with no ill effects.
I find prodding around in the registry slightly less scary than tweaking
unix/linux config files, though the required reboots thereafter are a pain
in the ar**.
Thanks again - and to all the Cygwin/XFree86 developers for an excellent
> -----Original Message-----
> From: firstname.lastname@example.org [mailto:email@example.com]On Behalf
> Of Jeff Mincy
> Sent: 06 January 2002 20:55
> To: Adrian Phillips
> Cc: James Hall; firstname.lastname@example.org
> Subject: Re: Newbie ssh question
> From: Adrian Phillips <email@example.com>
> Date: 06 Jan 2002 11:15:46 +0100
> >>>>> "James" == James Hall <firstname.lastname@example.org> writes:
> James> I've recently installed Cygwin and XFree86 on my W2K
> James> machine, and am highly pleased with it.
> James> Main use is to run stuff on my machine at work, and saves
> James> constantly re-booting between Windows and Linux on my home
> James> machine.
> James> I consequently make much use of ssh and X forwarding. All
> James> works excellently, but for one problem. Any remote Xterm,
> James> unless used pretty constantly, falls over with the message
> James> "Read from remote host x.x.x.x: Connection
> reset by peer
> James> Connection to x.x.x.x closed."
> Do you have a firewall in between. Firewalls throw away connections
> when there unused for a while,
> For example, Sonicwalls have Network Connection Inactivity Timeout
> Try turning on KeepALive (or whatever the option is called now),
> Also, there is how hard windows tries to keep connections alive.
> This is in the PuttyFAQ
> The timeout value can't be set on per application or per session
> basis. To increase the TCP timeout globally, you need to add the
> following key to the registry
> in Win95/98/ME (it must be DWORD in Win95, or String in Win98/ME),
> Then set the key's value to something like 10. This will cause
> Windows to try harder to keep connections alive instead of
> abandoning them.
> P.S. Have fun doing regedit.
> P.P.S, do be careful. This would be a good time to backup your machine.
> Your mouse has moved.
> Windows NT must be restarted for the change to take effect.
> Reboot now? [OK]
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