Re: [PATCH 1/1] tcp: Wrong timeout for SYN segments

From: Eric Dumazet <redacted>
Date: Fri, 31 Aug 2012 06:25:50 -0700

On Fri, 2012-08-31 at 14:48 +0200, Alexander Bergmann wrote:

quoted

Hi Eric!

I've also changed the Documentation file. As usual, comments are welcome!


Alex


From 848f34ce27f65401940ae98e0b2d395888d3986d Mon Sep 17 00:00:00 2001
From: Alexander Bergmann <redacted>
Date: Fri, 31 Aug 2012 14:31:00 +0200
Subject: [PATCH 1/1] tcp: Increase timeout for SYN segments

Commit 9ad7c049 changed the initRTO from 3secs to 1sec in accordance to
RFC6298 (former RFC2988bis). This reduced the time till the last SYN
retransmission packet gets sent from 93secs to 31secs.

RFC1122 is stating that the retransmission should be done for at least 3
minutes, but this seems to be quite high.

  "However, the values of R1 and R2 may be different for SYN
  and data segments.  In particular, R2 for a SYN segment MUST
  be set large enough to provide retransmission of the segment
  for at least 3 minutes.  The application can close the
  connection (i.e., give up on the open attempt) sooner, of
  course."

This patch increases the value of TCP_SYN_RETRIES to the value of 6,
providing a retransmission window of 63secs.

The comments for SYN and SYNACK retries have also been updated to
describe the current settings. The same goes for the documentation file
"Documentation/networking/ip-sysctl.txt".

Signed-off-by: Alexander Bergmann <redacted>
---

Thanks for your patience and followup, this seems good to me !

Acked-by: Eric Dumazet <edumazet@google.com>

Applied with some minor comment formatting and wording adjustments.

Thanks everyone.