From mboxrd@z Thu Jan  1 00:00:00 1970
From: Eric Dumazet <eric.dumazet@gmail.com>
Subject: Re: When TCP keepalives tuned shorter than retransmission timeouts
Date: Tue, 26 Nov 2013 08:20:22 -0800
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Cc: netdev@vger.kernel.org, David Miller <davem@davemloft.net>
To: Venkat Venkatsubra <venkat.x.venkatsubra@oracle.com>
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On Tue, 2013-11-26 at 07:51 -0800, Venkat Venkatsubra wrote:
> Some of our customers have tcp socket level options set to:
> TCP_KEEPIDLE 60
> TCP_KEEPINTVL 6 
> TCP_KEEPCNT 10
> 
> And when the peer is dead they expect the connection to timeout in 2 minutes instead of the
> 15 minutes from retransmission timeouts.
> (We know the tunables are set very low.)

Then change max number of retransmits : tcp_retries2 ?

Keepalive timer is not a way to defeat TCP exponential backoff.

Its really there to send probes when a session is idle.