Re: [PATCH 2/6] move ipvs to PRE/POSTROUTING

To: LVS Devel <lvs-devel@xxxxxxxxxxxxxxx>
Subject: Re: [PATCH 2/6] move ipvs to PRE/POSTROUTING
From: Jason Stubbs <j.stubbs@xxxxxxxxxxxxxxx>
Date: Fri, 18 Apr 2008 13:59:47 +0900
On Thursday 17 April 2008 15:59:47 Jason Stubbs wrote:
> On further investigation, the behaviour is the same regardless of whether
> it is a VIP or a real host. When a SYN_SENT state exists traffic doesn't
> flow. However, if there is no state and an ACK (no SYN) packet arrives, an
> ESTABLISHED entry is created such as:
> ipv4     2 tcp      6 431996 ESTABLISHED src= dst=
> sport=20001 dport=80 packets=1 bytes=54 [UNREPLIED] src=
> dst= sport=80 dport=20001 packets=0 bytes=0 mark=0 use=1
> After this the connection can complete normally. I wonder if this is not a
> bug in conntrack handling? It doesn't seem right to me.

There's an undocumented (as far as I can tell) sysctl that controls this 
called net.netfilter.nf_conntrack_tcp_loose which defaults to 1. Turning it 
off gave the behaviour I expected.

Jason Stubbs <j.stubbs@xxxxxxxxxxxxxxx>
東京都渋谷区桜ヶ丘町22-14 N.E.S S棟 3F
TEL 03-5728-4772  FAX 03-5728-4773
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