Odd Network Problem with FC5+

[Albert Graham]

Blake,

Is there some feature on your firewall that does some "intelligent" 
content filtering on port 23 ? which is skipped for your intranet ?,

if so disable that feature and re-test.

(I assume the machine is not under any load and the mail queue is empty 
- mailq)

I tried to connect from FC5, FC6 and RHEL 3 with the same results as 
you, and from 3 countries so I'm pretty sure its a local problem and not 
specific FC5 in anyway.

Al.

ps. I have a mail cluster sending 1m+ mails per day without any problems 
using FC5.


blake at ispn.net wrote:
> I seem to be having trouble sending mail from an FC5 server to
> mail.jococourthouse.com.
>
> The problem manifests itself as extreme slowness, which eventually leads
> to a timeout before I can even receive a full welcome prompt from the
> remote side.
>
> I have tested on ~ 10 boxes (different hardware) around the US ranging
> from FC5 through FC8 and NONE can telnet to this mx while RH, FC3 RH4,
> windows, and cisco gear on the same networks can ALL telnet without a
> problem.
>
> wireshark on the FC5 boxes show that the TCP handshake occurs as normal,
> however from then on all I receive from the remote side are 60 byte frames
> labeled 'TCP segment of a reassembled PDU' until I eventually receive an
> RST from the remote. - A capture on the working boxes looks normal.
>
> I suspect the problem is related to an IP/TCP change in the kernel or
> FC5+, however I have no idea what change could have occurred. Any insight
> or recommendations for resolving this problem would be appreciated.
>
>
> Thanks,
> -Blake
>
>