[clug] FTP nat timeout (linux Digest, Vol 107, Issue 9, Message 2)

[Miles Goodhew]

Hi Andrew,

On 9 November 2011 06:00,  <linux-request at lists.samba.org> wrote:
> Date: Tue, 08 Nov 2011 10:41:32 +1100
> From: Andrew <andrew at donehue.net>
> Message-ID: <4EB86CAC.8050109 at donehue.net>
>
> I'm trying to troubleshoot a connection reset after 24hrs.
>
> I have a Windows server -> CentOS router with a 2.6 kernel -> internet.
>
> The internet connection stays up without issue - just that a large FTP
> upload times out exactly 24hrs after starting.   The ftp tracking module
> is loaded on the server (and shorter ftp transfers work without issue).
>
> Any advice / hints appreciated.

  I think we need a bit more information - it sounds like the Windows
server is actually hosting the FTP client and the FTP server is
somewhere in the cloud. Knowing what FTP server is handling the
requests would be helpful. It's probably nothing to do with anything
other than the server or the client software, rather than any
networking inbetween (And the server's the most likely candidate). The
fact it's exactly 24H since transfer initiation suggest it's not a
problem with PPPoX/DHCP session renewal.
  Other than that I'd suggest using incremental rsync instead ("rsync
--partial [SRC] [USER at HOST]:[DST]") or failing that maybe you can
wangle an FTP-send resume somehow. Regarless, having such long-lived
connections using FTP (An archaic, weird, not fully standardised
protocol prone to hackish extensions in various implementations) is a
risky endeavor.

M0les.

-- 
Miles Goodhew,
Executive Computer Scientist