netdev - Re: [PATCH] tcp FRTO: in-order-only "TCP proxy" fragility workaround

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Date:	Sun, 24 Aug 2008 16:38:43 -0300
From:	Dâniel Fraga <fragabr@...il.com>
To:	"Ilpo Järvinen" <ilpo.jarvinen@...sinki.fi>
Cc:	David Miller <davem@...emloft.net>, thomas.jarosch@...ra2net.com,
	billfink@...dspring.com, Netdev <netdev@...r.kernel.org>,
	Patrick Hardy <kaber@...sh.net>,
	netfilter-devel@...r.kernel.org, kadlec@...ckhole.kfki.hu
Subject: Re: [PATCH] tcp FRTO: in-order-only "TCP proxy" fragility
 workaround

On Sat, 23 Aug 2008 17:38:32 +0300 (EEST)
"Ilpo Järvinen" <ilpo.jarvinen@...sinki.fi> wrote:

> Thanks for verifying it!

	Ops! i replied too fast! I just got a stalled connection again!

	Important: these files were generated with the HTB patches applied.

	Here are botch tcpdump files:

http://www.abusar.org/htb/dump-mail-server.log
http://www.abusar.org/htb/dump-mail-client.log

	Both readmibs:

http://www.abusar.org/htb/readmibs-server.txt
http://www.abusar.org/htb/readmibs-client.txt

	Here are both cat /proc/net/tcp:

http://www.abusar.org/htb/tcp-server.txt
http://www.abusar.org/htb/tcp-client.txt

	I use the following to generate those dumps:

	1) on the server:

tcpdump -s 0 -w dump-mail-server.log -i eth0 host 201.52.214.230

	2) on the client:

tcpdump -s 0 -w dump-mail-client.log -i eth0 host teleporto.abusar.org and port 995

	What happened?

1) the connection was stalled

2) these tcpdumps are the *best ones* I got because although I started them with
the connection already stalled, the connection suddenly is not stalled anymore,
and a few minutes later was stalled again...

3) I keep tcpdump running for more time
	
	Ps: anyway I could notice that the only two services that
remain stalled is nntp, ftp, pop3 and smtp... http is never stalled,
neither ssh. It seems to affect only "old" protocols :)

	Ps2: anyway, the htb patch seems to help, because the problem
took much longer to happen. With htb patches the problem happens one time a day. 
Without the htb patches the problem happens more than one time a day.

	Ps3: I really doesn't understand why "nmap -sS server"
"solves" the stalled connection issue.

	Ps4: sorry for my hurry feedback before. I thought the problem had gone. Anyway, 
I hope this time I provided the best data for you. Thanks.

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