This sounds a little like a problem that was reported to the bugtraq
list last week.
There are some places that are sending back broken packets. From memory,
it was in response to pactkets setting socket options and these options
were sent back as data. This primarily affects linux systems.
On Sat, Apr 01, 2000 at 07:39:13AM +1000,
Jon Jenkins <[EMAIL PROTECTED]> wrote:
> Greetings,
>
> I'm having a problem whereby SMTP connections from certain mail-servers work
> fine and from other servers there is a big problem (all packets appear to
> disappear or get disregarded). Most of the ISP's servers fail (including the
> secondary MX).
>
> The ISP has:
> 1) Traced the packets as far as the ISDN router.
> 2) Double checked the router config.
> and say that everything is fine ...
>
> The router (CISCO 801) maps ports 25 and 53(TCP & UDP) through to the SCO
> box.
>
> qmail-smtpd is running under tcpserver with -v for logging purposes ...
>
> The config for qmail is very simple.
>
> Some servers at the ISP can (and do) telnet to port 25 and get a "good"
> connect and manage to get through the smtp session and mail entered is
> delivered.
>
> Others receive the "banner" but everything else sent gets "lost" and
> eventually
> the session times-out.
>
> There are no "deny's" on the router or on SCO,(that I can find)
>
> What can any-one suggest ... depression is setting in.
>
> Jon Jenkins
>
>
>
