Damien Miller djm at
Fri Feb 26 18:10:43 EST 2010

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" 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


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