ISP port blocking practice

Sat Oct 24 03:36:18 UTC 2009

On Fri, Oct 23, 2009 at 5:43 PM, Justin Shore <justin at justinshore.com> wrote:
>[...]   Just because someone bought themselves a
>Camry doesn't mean that Toyota is deciding for them that they can't haul
> 1000lbs of concrete with it. [...]

Server does not necessarily equal business.      A server that handles
 a few personal mailboxes for a residential user is not 1000lbs of
concrete.
Offhand, I can think of a lot of uses for various types of servers at
a residence that don't require special business features, and are
generallly  low-traffic.

Some people might be a little upset if they brought their brand new
leased Camry home, to find their particular  dealer had made an
ad-hoc  decision to  weld the trunk shut, and didn't tell them about
it directly and immediately,  when advertising the vehicle.

You want to haul a few groceries home?   Shoulda  asked for a  "business" camry.

Nevermind that the manufacturer has no separate product for that,  it
was a dealer's arbitrary decision to block that particular "port",
anticipating customers would otherwise try to do evil things with it
(like try to haul concrete).

Anyways...   like it or not..    blocking of  outbound/inbound 25  may
be common.
But how common was the original question..   not  'is it a good idea?' or not.

I would suggest that blocking the destination port 25, outgoing
traffic from the end-user's point of view is the more preferred
choice,    it is more efficient,  in that the block is closer  to the
source, and there are fewer wasted bits of traffic.

--
-J