In my setup I sometimes have to put my computer to hibernate when I have
one or more ssh (OpenSSH, in fact) connections to remote hosts. My
hibernate setup is such that when I bring my computer back to life the
network is up and running immediately. However, my ssh connections to
remote hosts take some 10-15 minutes to revive.

Anybody know why that should be the case? Anybody know if there is some
OpenSSH configuration parameter that would get the ssh connections back to
life quickly?

Augustus SFX van Dusen <ASFXvD@story.net> writes:

> In my setup I sometimes have to put my computer to hibernate when I have
>one or more ssh (OpenSSH, in fact) connections to remote hosts. My
>hibernate setup is such that when I bring my computer back to life the
>network is up and running immediately. However, my ssh connections to
>remote hosts take some 10-15 minutes to revive.

> Anybody know why that should be the case? Anybody know if there is some
>OpenSSH configuration parameter that would get the ssh connections back to
>life quickly?

I hae the same problem when my network goes down for a while (ISP problems)
I sometimes find that opening a new ssh to the same host revives teh old
one. Not sure where the problem is-- whetehr it is a long timeout in the
local or in the remote ssh.(It has never been 15 min, but that may depend
on the length of the down time)

On Sun, 24 Sep 2006 23:21:39 +0000, Unruh wrote:

> Augustus SFX van Dusen <ASFXvD@story.net> writes:
>
>> In my setup I sometimes have to put my computer to hibernate when I have
>>one or more ssh (OpenSSH, in fact) connections to remote hosts. My
>>hibernate setup is such that when I bring my computer back to life the
>>network is up and running immediately. However, my ssh connections to
>>remote hosts take some 10-15 minutes to revive.
>
>> Anybody know why that should be the case? Anybody know if there is some
>>OpenSSH configuration parameter that would get the ssh connections back
>>to life quickly?
>
> I hae the same problem when my network goes down for a while (ISP
> problems) I sometimes find that opening a new ssh to the same host revives
> teh old one. Not sure where the problem is-- whetehr it is a long timeout
> in the local or in the remote ssh.(It has never been 15 min, but that may
> depend on the length of the down time)

For what it's worth, I think I have found a solution to my problem
(not for the first time immediately after asking for a answer to some
question in the net either). If in my /etc/ssh/ssh_config I enter the
lines

ServerAliveCountMax 1
ServerAliveInterval 10

then my connections seem to come back quickly enough after reviving my
computer.

Augustus SFX van Dusen <ASFXvD@story.net> writes:

>On Sun, 24 Sep 2006 23:21:39 +0000, Unruh wrote:

>> Augustus SFX van Dusen <ASFXvD@story.net> writes:
>>
>>> In my setup I sometimes have to put my computer to hibernate when I have
>>>one or more ssh (OpenSSH, in fact) connections to remote hosts. My
>>>hibernate setup is such that when I bring my computer back to life the
>>>network is up and running immediately. However, my ssh connections to
>>>remote hosts take some 10-15 minutes to revive.
>>
>>> Anybody know why that should be the case? Anybody know if there is some
>>>OpenSSH configuration parameter that would get the ssh connections back
>>>to life quickly?
>>
>> I hae the same problem when my network goes down for a while (ISP
>> problems) I sometimes find that opening a new ssh to the same host revives
>> teh old one. Not sure where the problem is-- whetehr it is a long timeout
>> in the local or in the remote ssh.(It has never been 15 min, but that may
>> depend on the length of the down time)

> For what it's worth, I think I have found a solution to my problem
>(not for the first time immediately after asking for a answer to some
>question in the net either). If in my /etc/ssh/ssh_config I enter the
>lines

> ServerAliveCountMax 1
> ServerAliveInterval 10

While the latter looks useful, the former seems counterproductive, at least
in my situations. Ie, it says that if once the server does not respond to
the ServerAlive message, you are disconnected. That seems pretty harsh.


>then my connections seem to come back quickly enough after reviving my
>computer.

On Mon, 25 Sep 2006 16:57:51 +0000, Unruh wrote:

> Augustus SFX van Dusen <ASFXvD@story.net> writes:
>
>>On Sun, 24 Sep 2006 23:21:39 +0000, Unruh wrote:
>
>>> Augustus SFX van Dusen <ASFXvD@story.net> writes:
>>>
>>>> In my setup I sometimes have to put my computer to hibernate when I
>>>> have
>>>>one or more ssh (OpenSSH, in fact) connections to remote hosts. My
>>>>hibernate setup is such that when I bring my computer back to life the
>>>>network is up and running immediately. However, my ssh connections to
>>>>remote hosts take some 10-15 minutes to revive.
>>>
>>>> Anybody know why that should be the case? Anybody know if there is
>>>> some
>>>>OpenSSH configuration parameter that would get the ssh connections back
>>>>to life quickly?
>>>
>>> I hae the same problem when my network goes down for a while (ISP
>>> problems) I sometimes find that opening a new ssh to the same host
>>> revives teh old one. Not sure where the problem is-- whetehr it is a
>>> long timeout in the local or in the remote ssh.(It has never been 15
>>> min, but that may depend on the length of the down time)
>
>> For what it's worth, I think I have found a solution to my problem
>>(not for the first time immediately after asking for a answer to some
>>question in the net either). If in my /etc/ssh/ssh_config I enter the
>>lines
>
>> ServerAliveCountMax 1
>> ServerAliveInterval 10
>
> While the latter looks useful, the former seems counterproductive, at
> least in my situations. Ie, it says that if once the server does not
> respond to the ServerAlive message, you are disconnected. That seems
> pretty harsh.

I guess it is. I use a combination of autossh and screen though, which
so far seems to work fine with such settings.


>
>>then my connections seem to come back quickly enough after reviving my
>>computer.

In comp.security.ssh Unruh <unruh-spam@physics.ubc.ca>:
> Augustus SFX van Dusen <ASFXvD@story.net> writes:

>>On Sun, 24 Sep 2006 23:21:39 +0000, Unruh wrote:

>>> Augustus SFX van Dusen <ASFXvD@story.net> writes:

>>>> In my setup I sometimes have to put my computer to hibernate when I have
>>>>one or more ssh (OpenSSH, in fact) connections to remote hosts. My
>>>>hibernate setup is such that when I bring my computer back to life the
>>>>network is up and running immediately. However, my ssh connections to
>>>>remote hosts take some 10-15 minutes to revive.

>>>> Anybody know why that should be the case? Anybody know if there is some
>>>>OpenSSH configuration parameter that would get the ssh connections back
>>>>to life quickly?

>>> I hae the same problem when my network goes down for a while (ISP
>>> problems) I sometimes find that opening a new ssh to the same host revives
>>> teh old one. Not sure where the problem is-- whetehr it is a long timeout
>>> in the local or in the remote ssh.(It has never been 15 min, but that may
>>> depend on the length of the down time)

Mostly a ssh connection can survive such thing easily with static
IP, if you just keep the xterm with the login open. YMMV

>> For what it's worth, I think I have found a solution to my problem
>>(not for the first time immediately after asking for a answer to some
>>question in the net either). If in my /etc/ssh/ssh_config I enter the
>>lines

>> ServerAliveCountMax 1
>> ServerAliveInterval 10

> While the latter looks useful, the former seems counterproductive, at least
> in my situations. Ie, it says that if once the server does not respond to
> the ServerAlive message, you are disconnected. That seems pretty harsh.

The above would disconnect the unresponsive session 10 seconds
after the first packet got no answer as per client side
configuration.

Indeed this is more useful on the sshd side to stop firewalls
from automatic disconnecting idle sessions there are far better
ways to do this then a firewall could. but although to let sshd
disconnect broken sessions cleanly, without "filling" up utmp an
associated tools with ghost logins.

ClientAliveCountMax
ClientAliveInterval

Default of the later is zero, disabling sending messages to the
client at all.

--
Michael Heiming (X-PGP-Sig > GPG-Key ID: EDD27B94)
mail: echo zvpunry@urvzvat.qr | perl -pe 'y/a-z/n-za-m/'
#bofh excuse 225: It's those computer people in X {city
of world}. They keep stuffing things up.