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From: Flavio Leitner <fbl@sysclose.org>
To: netdev@vger.kernel.org
Subject: TCP keepalive question
Date: Fri, 16 Apr 2010 12:06:44 -0300	[thread overview]
Message-ID: <20100416150644.GA2641@sysclose.org> (raw)

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Hi,


I'm reading the RFC 1122 and it says the following:
...
           Keep-alive packets MUST only be sent when no data or
           acknowledgement packets have been received for the
           connection within an interval.  
...

The receiving acknowledgement part seems to be ok and handled 
by tcp_keepalive_timer() when it does 
elapsed = tcp_time_stamp - tp->rcv_tstamp;

However, if one side just receive data and reply with ACK, the
keepalive probes is sent anyway - 2.6.32.9-70.fc12.i686.PAE.

Any reason to not reset keepalive timer when data is received?

Socket options used:
SO_KEEPALIVE, TCP_KEEPIDLE=40, TCP_KEEPCNT=6, TCP_KEEPINTVL=5

Traffic dump attached.

thanks!
-- 
Flavio

[-- Attachment #2: keepalive.pcap.gz --]
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             reply	other threads:[~2010-04-16 15:07 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-04-16 15:06 Flavio Leitner [this message]
2010-04-17 17:28 ` [PATCH] TCP: avoid to send keepalive probes if it is receiving data Flavio Leitner
2010-04-18  9:06   ` Eric Dumazet
2010-04-18 14:55     ` [PATCH v2] " Flavio Leitner
2010-04-18 17:15       ` Eric Dumazet
2010-04-18 20:34         ` Ilpo Järvinen
2010-04-22  5:42           ` David Miller
2010-04-25 23:55             ` Flavio Leitner
2010-04-26  2:40               ` [PATCH v3] TCP: avoid to send keepalive probes if " Flavio Leitner
2010-04-26  9:47                 ` Ilpo Järvinen
2010-04-26 18:24                   ` David Miller
2010-04-27  4:33                     ` [PATCH v4] " Flavio Leitner
2010-04-27  5:06                       ` Eric Dumazet
2010-04-27  6:08                       ` Ilpo Järvinen
2010-04-27 19:55                         ` David Miller
2010-04-25 23:44         ` [PATCH v2] TCP: avoid to send keepalive probes if it is " Flavio Leitner

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