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List:       linux-server
Subject:    Re: stuck smtp
From:       Pluto <pluto () PIZZASERVICE ! DE>
Date:       1998-10-30 0:59:42
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On Thu, 29 Oct 1998, Alan Cox wrote:

> >   I'm at wits end. A customers gateway send's smal mail ok, but larger
> > ones (>3k) get stuck and netstat reports 95% of the mail stuck in Send Q.
> > Kernel is 2.0.35, Sendmail 8.8.8, uplink is ether to the backbones switch,
> > masqueraded intranet behind.
>
> That typically suggests path mtu problems. Make sure you have icmp
> masquerading services on and are not blocking icmp coming back

  The same happend when sending from the gateway itself. What I didn't
noticed was that every traffik to the switch got scrambled, not only smtp,
telnet to the gateway and "ls -l /" produced enought kB to prduce this
effect.

  I still haven't found the reason for this, but the solution was to
exchange the el cheapo ne2k for a 3c905 and voila no more losses. The 3Com
1100 showed large amounts of crc errors when doing more than nothing
traffic and tcpdump reported garbage, it thougt it would be getting smb
packets :) Duplex was set to half by the switch, so this isn't likely to
be the reason, I'd think.

  Cheers

  Pluto   -   SysAdmin of Hades
  Free information! Freedom through knowledge. Wisdom for all!! =:-)
  PGP 1024/7261AACD 1996/09/10 1F3F EA94 D056 A686  4D19 C456 6CF9 4344

  RL is just another window ...

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