[129362] in North American Network Operators' Group
Re: ISP port blocking practice
daemon@ATHENA.MIT.EDU (Owen DeLong)
Fri Sep 3 13:03:45 2010
From: Owen DeLong <owen@delong.com>
To: NANOG list <nanog@nanog.org>
In-Reply-To: <4C810867.10202@gmail.com>
Date: Sat, 4 Sep 2010 02:30:06 +0930
Cc: NANOG list <nanog@nanog.org>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
I have had it happen in some metro areas on sprint. I have experienced =
it in at least a dozen hotels over the last 12 months. I have run into =
it in various airports with free public wifi. I have run into the =
problem in several coffee shops.
By far, the worst offenders are the most expensive hotels where the =
Internet access, damaged as it is generally goes for $25+ per day. I =
almost always end up getting free Internet as a result because I report =
the issue as a problem and their technical support usually can't spell =
tcp let alone understand what I mean when I say a port is blocked.
Even worse is the ones that silently redirect your smtp (regardless of =
port) session to their MTA. Fortunately, my configuration is good enough =
that it just breaks in these cases, but I know many people who thought =
they were connecting to their own server via TLS only to later discover =
that their mail was relayed in clear text through several third party =
servers. (most mua's seem to have an unfortunate default to "ssl or tis =
if available" and keep right on sending even if tis negotiations are =
rejected.)
Owen
Sent from my iPad
On Sep 4, 2010, at 12:08 AM, JC Dill <jcdill.lists@gmail.com> wrote:
> Patrick W. Gilmore wrote:
>> On Sep 3, 2010, at 8:22 AM, Owen DeLong wrote:
>> =20
>>> On Sep 2, 2010, at 10:41 PM, Franck Martin wrote:
>>>=20
>>> =20
>>>> Have you heard of the submission port?
>>>>=20
>>>> =20
>>> Yes... Many of the idiots that block outbound 25 also block outbound =
587 and sometimes 465.
>>> =20
>>=20
>> Could you point to more than one instance? I've not yet found one. =
And I think I spend at least as much time in hotels & 3G & airports & =
etc. as you anyone else here.
>>=20
>> =20
> FWIW, I had it happen at a local library. Used their webform to send =
a message mentioning that blocking 25 was good, but blocking 587 and 465 =
was bad. It took several days but they did fix it.
>=20
> jc
>=20
