Subject: Re: [BUG bisected] 2.6.30.4: NET: active FTP doesn't work

From: Patrick McHardy <[email-masked]>
Date: Wed, 26 Aug 2009 14:51:23 +0200

Vitezslav Samel wrote:
> 	Hi!
> 
>   When testing 2.6.30.4+ kernel, I discovered active ftp does not work
> anymore (2.6.30.3 is OK).
> 
>                LAN              internet
>    machine1  -------  router1   -------   machine2
> 
> 
>  Active ftp from machine1 to machine2 connects, transfers some files and
> then hangs. Passive ftp works OK. The faulty box (router1)
> is router/firewall and is doing NAT.
> 
>   I bisected it down to commit 7500f93f415a2fc07e0031d99fa3964bf8981cfc
> in linux-2.6.30.y tree ("netfilter: tcp conntrack: fix unacknowledged
> data detection with NAT").
> 
>   Could you, please, take look at it?

Please send me a tcpdump (binary dump, with -o <file> and -s0) of an
FTP session on both the internal and external interfaces and your NAT
rules. Thanks.