Remote ssh server stalls
Joaco
servers. Whether I use ssh or telnet, if I stop hitting the
kbd, on the logged session, for more than several minutes,
the remote ssh server goes to sleep and the kbd is dead.
I assume this is a configuration problem, but where is this
timeout set or how can this behaviour be stopped?
thanks in advance
TonyB
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Keith Keller
> I connect via a login session between two of my internet
> servers. Whether I use ssh or telnet, if I stop hitting the
> kbd, on the logged session, for more than several minutes,
> the remote ssh server goes to sleep and the kbd is dead.
>
> I assume this is a configuration problem, but where is this
> timeout set or how can this behaviour be stopped?
You can look at the TCPKeepAlive option for sshd_config, but
it's set by default.
By chance is the server on the other side of a cheap router like
D-Link or Netgear? I have a Netgear MR314, and sshd sessions would
die as you describe above after two or three minutes of idle time.
TCPKeepAlive in my sshd_config didn't solve this problem last I
tried.
--keith
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Joaco
Keith Keller <kkeller...@wombat.san-francisco.ca.us> wrote:
> On 2005-07-07, Joaco <to...@sysdev.org> wrote:
> > I assume this is a configuration problem, but where is this
> > timeout set or how can this behaviour be stopped?
>
> You can look at the TCPKeepAlive option for sshd_config, but
> it's set by default.
It has: KeepAlive yes
but no: TCPKeepAlive option
>
> By chance is the server on the other side of a cheap router like
> D-Link or Netgear?
No Keith, the server is the router. Directly connected to my DSL
WireSpeed modem and running an upgraded Slackware 9.1
Tony
The Eighth Doctor
says...
Tony I must be missing something. Your server is posing as the router, he's directly
connected to the I'net via the standard DSL modem. There isn't any of the cheap
routers involved, or even a moderately priced one, like my LinkSys. I suggest you
complain to your ISP, surely there's an intelligent invidual there who understands
Linux as well as we do. And also double check your settings.
--
Gregg drwho8 atsign att dot net
Joaco
drwho8_...@att.net (The Eighth Doctor) wrote:
> In article <20050706203329...@sysdev.org>,
> to...@sysdev.org says...
> >
> >On Wed, 6 Jul 2005 20:34:13 -0700
> >Keith Keller <kkeller...@wombat.san-francisco.ca.us> wrote:
> >
> >> On 2005-07-07, Joaco <to...@sysdev.org> wrote:
> >
> >> > I assume this is a configuration problem, but where is this
> >> > timeout set or how can this behaviour be stopped?
> >>
> >> You can look at the TCPKeepAlive option for sshd_config, but
> >> it's set by default.
> >
> >It has: KeepAlive yes
> >but no: TCPKeepAlive option
> >
> >>
> >> By chance is the server on the other side of a cheap router like
> >> D-Link or Netgear?
> >
> >No Keith, the server is the router. Directly connected to my DSL
> >WireSpeed modem and running an upgraded Slackware 9.1
> >
> Hello from the Eighth Doctor
> Tony I must be missing something. Your server is posing as the
> router, he's directly connected to the I'net via the standard DSL
> modem. There isn't any of the cheap routers involved, or even a
> moderately priced one, like my LinkSys. I suggest you complain to
> your ISP, surely there's an intelligent invidual there who
> understands Linux as well as we do. And also double check your
> settings.--
> Gregg drwho8 atsign att dot net
You have it right. There is one other suspect, I connect with my
client host via a T-Mobile internet connection. However, other
connections with T-Mobile, like to my yahoo mail, irc, xchat,
ftp do not hang after idle times of 5+minutes.
use...@isbd.co.uk
> On 2005-07-07, Joaco <to...@sysdev.org> wrote:
> > I connect via a login session between two of my internet
> > servers. Whether I use ssh or telnet, if I stop hitting the
> > kbd, on the logged session, for more than several minutes,
> > the remote ssh server goes to sleep and the kbd is dead.
> >
> > I assume this is a configuration problem, but where is this
> > timeout set or how can this behaviour be stopped?
>
> You can look at the TCPKeepAlive option for sshd_config, but
> it's set by default.
>
the session is still connected and, if it's NOT connected it issues an
error message and exits from ssh. See 'man ssh_config'.
> By chance is the server on the other side of a cheap router like
> D-Link or Netgear? I have a Netgear MR314, and sshd sessions would
> die as you describe above after two or three minutes of idle time.
> TCPKeepAlive in my sshd_config didn't solve this problem last I
> tried.
>
In my case it's the firewalls between work and outside that detect no
traffic and disconnect the session. What I have is a trivial program that
I start in the background on the server end of the session when I connect
that simply sends a NUL character across the link every few minutes.
--
Chris Green
Douglas Mayne
> I connect via a login session between two of my internet
> servers. Whether I use ssh or telnet, if I stop hitting the
> kbd, on the logged session, for more than several minutes,
> the remote ssh server goes to sleep and the kbd is dead.
>
> I assume this is a configuration problem, but where is this
> timeout set or how can this behaviour be stopped?
>
> thanks in advance
> TonyB
>
I had this problem, too. I fixed it by setting this value in sshd_config:
ClientAliveInterval 90
man sshd_config
My problem is caused by quick timeouts of established connections at
the DSL Modem (an Actiontec 1524, in my case.) The modem's built in
firewall has limited functionality. I am tempted to bypass it totally
using its "DMZ forwarding" feature to see if another device would work
better. Short of that, the "keep alive probes" (above) work for ssh.
The equivalent setting may exist for other protocol daemons, but maybe not
(Lotus Domino, for example).