From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: [PATCH 1/1] tcp: Wrong timeout for SYN segments Date: Thu, 23 Aug 2012 14:49:45 +0200 Message-ID: <1345726185.5904.835.camel@edumazet-glaptop> References: <503419D3.1080700@linlab.net> <50361AEA.6010807@linlab.net> <1345724123.5904.756.camel@edumazet-glaptop> <50362407.9070805@linlab.net> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: "H.K. Jerry Chu" , davem@davemloft.net, netdev@vger.kernel.org, linux-kernel@vger.kernel.org To: Alex Bergmann Return-path: In-Reply-To: <50362407.9070805@linlab.net> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Thu, 2012-08-23 at 14:37 +0200, Alex Bergmann wrote: > > From be551f82499112e4775b6d579d58967510b6d492 Mon Sep 17 00:00:00 2001 > From: Alexander Bergmann > Date: Thu, 23 Aug 2012 14:33:35 +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.[1] > > This patch increases the value of TCP_SYN_RETRIES to the value of 6, > providing a retransmission window of 63secs. > > [1] RFC 1122 - 4.2.3.5 TCP Connection Failures > > Signed-off-by: Alexander Bergmann > --- > include/net/tcp.h | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/include/net/tcp.h b/include/net/tcp.h > index 1f000ff..f309e93 100644 > --- a/include/net/tcp.h > +++ b/include/net/tcp.h > @@ -98,7 +98,7 @@ extern void tcp_time_wait(struct sock *sk, int state, int timeo); > * 15 is ~13-30min depending on RTO. > */ > > -#define TCP_SYN_RETRIES 5 /* number of times to retry active opening a > +#define TCP_SYN_RETRIES 6 /* number of times to retry active opening a > * connection: ~180sec is RFC minimum */ > > #define TCP_SYNACK_RETRIES 5 /* number of times to retry passive opening a Acked-by: Eric Dumazet A change of the comment might be good, to help future readers.