On Wed, Jun 20, 2007 at 04:16:00PM +0200, Joerg Sonnenberger wrote:
> On Wed, Jun 20, 2007 at 09:58:23AM -0400, Greg Troxel wrote:
> >   keepalive interval should be well greater than RTT
> 
> In practise, the lower bound must be > RTT x max_retries. Using that
> should be as good enough though.
> 
> >   keepalive intercal should only be short enough to keep broken nat
> >   boxes working
> 
> Using a low setting can be also be used to detect dead machines, so I
> can understand why using the above could be a good idea.

Except that it doesn't make any sense to set it lower than TCP
retransmition timer.

(Actually, and IIRC, all the keepalive timeout does is force the
retransmit timout sequence to start.  Last time I timed this (on
a Linux box) it took 10s of minutes to disconnect after the first
keepalive got sent.)

	David

-- 
David Laight: david@l8s.co.uk