IdleTimeout patch did not get in?

Darren Tucker dtucker at
Mon Jun 25 07:48:05 EST 2007

On Sun, Jun 24, 2007 at 12:54:27PM -0400, B Wooster wrote:
> On 6/24/07, Darren Tucker <dtucker at> wrote:
> > What you need to do is remove all keepalives.  The problem is that as soon
> > as the server generates any traffic (be that ClientAlive* or TCPKeepAlive)
> > then TCP guarantees that that the data will get to the other end or
> > the application will be notified.  Keepalives just guarantee that the
> > (apparent) connection failure will be detected and your connection will
> > be killed when the client becomes unresponsive.
> Thanks - I'll test this out - need 8 hours to test!
> ClientAliveInterval was set to 0, so that was correct.
> TCPKeepAlive was set to yes - I've set it to no, and re-started server
> and re-connected, let's see what happens tomorrow.
> Anyone know at what interval does the OpenSSH server send the
> TCPKeepAlive? It is larger than 30 minutes - I sent my machine into
> standby for 30 minutes, and after waking up, I still had the
> connection (this was before I changed TCPKeepAlive to no).

Normally TCP keepalives are enabled or disabled on a per-connection
basis, but the keepalive timer is system-wide.  On many systems the
default value is 2 hours.

Darren Tucker (dtucker at
GPG key 8FF4FA69 / D9A3 86E9 7EEE AF4B B2D4  37C9 C982 80C7 8FF4 FA69
    Good judgement comes with experience. Unfortunately, the experience
usually comes from bad judgement.

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