ClientAliveInterval

[Damien Miller]

On Fri, 26 Feb 2010, Sayan Chaliha wrote:

> @Damien, could you also tell me what would happen if the client didn't
> respond to that request, and instead tried to create new session and channel
> afresh? Would the server send the same message again?

A client that is compliant with the protocol _must_ respond, even just to
say "I have no idea what this command is". Any response will reset the
keepalive timer.

> On Fri, Feb 26, 2010 at 12:40 PM, Damien Miller <djm at mindrot.org> wrote:
> 
> > On Fri, 26 Feb 2010, Sayan Chaliha wrote:
> >
> > > Hi,
> > >
> > > I am having some trouble with the ClientAliveInterval server setting. My
> > > (C++) application fails to start an SSH channel to an OpensSSH server
> > within
> > > this time-out period if it doesn't reply correctly to this 'keep-alive'
> > > no-op that is sent by the server. How is this no-op handled? I am using
> > the
> > > libssh client library, and I could find no references on how to handle
> > this.
> >
> > Client aliver interval is implemented by sending a global or channel
> > request of type "keepalive at openssh.com" with want-reply turned on.
> > You shouldn't need to implement anything for this to work - a client
> > should return SSH2_MSG_REQUEST_FAILURE if it doesn't implement this request
> > type and that should be enough to reset the keepalive watchdog timer.
> >
> > If you would like to explicitly support it, you can just send an
> > approprate SSH2_MSG_REQUEST_SUCCESS (global request) or
> > SSH2_MSG_CHANNEL_SUCCESS (channel request) message, but this is purely
> > optional.
> >
> > -d
> >
> 
> 
> 
> -- 
> Regards,
> Sayan Chaliha
> Webyog Softworks Private Limited
> 2nd Floor, Novel Team Building
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> 
> +91-9743357501
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