[118511] in North American Network Operators' Group
Re: ISP port blocking practice
daemon@ATHENA.MIT.EDU (Ricky Beam)
Thu Oct 22 17:37:41 2009
To: "Zhiyun Qian" <zhiyunq@umich.edu>, "NANOG list" <nanog@nanog.org>
Date: Thu, 22 Oct 2009 17:37:03 -0400
From: "Ricky Beam" <jfbeam@gmail.com>
In-Reply-To: <0A08271D-49B9-4382-9F54-1A0BB6A3F2B2@umich.edu>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
On Thu, 22 Oct 2009 13:22:17 -0400, Zhiyun Qian <zhiyunq@umich.edu> wrote:
> 1). For any outgoing traffic, if the destination port is 25, then drop
> the packets.
> 2). For any incoming traffic, if the source port is 25, then drop the
> packets.
Inspecting outgoing traffic is generally easier to do as there's less of
it. (in a consumer context, which is the only place such filtering makes
any sense.)
--Ricky
