[123378] in North American Network Operators' Group
Re: Problem from Comcast Network to The Planet
daemon@ATHENA.MIT.EDU (Steven Bellovin)
Fri Mar 5 16:42:37 2010
From: Steven Bellovin <smb@cs.columbia.edu>
In-Reply-To: <9805C6F4-6E91-4F47-9458-2005774D7C87@gmail.com>
Date: Fri, 5 Mar 2010 16:41:03 -0500
To: Zachary Frederick <zcfrederick@gmail.com>
Cc: nanog@nanog.org
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
On Mar 5, 2010, at 4:33 PM, Zachary Frederick wrote:
> We have been having a problem emailing to a customer whose server is =
hosted by The Planet (http://www.theplanet.com/). Our mail server is =
hosted in-house on a comcast business connection.
>=20
> IP address of our server is: 173.13.45.23
>=20
> Customers mail server is: 69.93.203.243
>=20
> I cannot telnet to port 25 on their server, and they cannot telnet to =
port 25 on ours.
>=20
> If I try to connect to their mail server from a different network such =
as my home internet connection, I can connect.
> We do not do any firewalling that would block this in anyway. We were =
able to send and receive email to them when we used Qwest for our =
connection, before we switched to Comcast.
>=20
> Comcast has said the problem is not on their end because it times out =
at The Planet.
> The Planet doesn't have much interest in speaking with me, because I'm =
not their customer.
>=20
> Not sure what to do at this point.
>=20
> Below is a traceroute:
If you have a suitable platform, try tcptraceroute and see where port 25 =
is blocked.=
