[TriLUG] Email issues

[S B]

>>> Maybe someone in there is still having trouble with ECN
Is it possible I have the ECN bit set, so the destination feels entitled to 
drop the packets (for some reason) ?

>>> tcptraceroute might be able to help you detect a broken hop in there 
>>> somewhere.
All actions are from the shell of the dedicated server (obviously I can't go 
the other way, from the shell of the shared account).

(1) traceroute takes 10 hops to get to the shared hosting provider boundary 
and then no responses (just 20 loads of  " * * * ").
This is true for the shared server that had the SMTP/HTTP  problem, *and* 
the one that didn't have the problem.

2) If I ping the shared servers, the one with the SMTP/HTTP problem doesN'T 
respond but with server without the SMTP/HTTP problem *does* respond.

3) If I telnet to port 25 (SMTP) on the shared servers, again the one with 
the SMTP/HTTP problem doesN'T respond but with server without the SMTP/HTTP 
problem *does* respond.


If I repeat step (1) (2) and (3) from my Roadrunner home connection, both 
shared hosting servers respond correctly !

Simon...

www.BeGreenForum.com
Practical Eco Friendly Information and Discussion.

----- Original Message ----- 
From: "Brad Jorsch" <anomie at users.sourceforge.net>
To: "Triangle Linux Users Group discussion list" <trilug at trilug.org>
Sent: Friday, February 02, 2007 5:00 PM
Subject: Re: [TriLUG] Email issues


> On Fri, Feb 02, 2007 at 03:00:44PM -0500, S B wrote:
>>
>> I forgot to mention earlier that I was also trying to establish a HTTP
>> connection between the 2 hosts (using PHP cURL), and that too timed-out, 
>> so
>> I think it's more general than just SMTP connections but only applies to
>> certain (few) combinations of hosts.
>
> Have you checked your firewalls? A tcpdump might also tell you if the
> packets are getting to the right host.
>
> It could also be someone somewhere trying to be "helpful" with a
> firewall on a router. Maybe someone in there is still having trouble
> with ECN or something, or i've had trouble in the past once or twice
> when dialup woud give me an address ending in .255.
>
> tcptraceroute might be able to help you detect a broken hop in there
> somewhere.
>
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