Re: [fw-wiz] Port numbers for Peer to Peer file sharing apps.

From: Eric Vyncke (
Date: 11/22/02

To: Mikael Olsson <>
From: Eric Vyncke <>
Date: Fri Nov 22 08:34:33 2002

At 10:50 22/11/2002 +0100, Mikael Olsson wrote:

>Eric Vyncke wrote:
>> If you are concerned only by the waste of bandwidth, you may want to:
>> - block all incoming TCP connections but the really needed ones
>Um. That doesn't work for kazaa (fasttrack), gnutella, etc.
>These apps will detect if they're firewalled, and if two peers want
>to talk to eachother where one side is firewalled, the connection
>will always be initiated by the firewalled one.

Right, but my point was that those applications require at least one peer without firewall (= accepting incoming connection). So, blocking incoming connections will cut the bandwidth by at least 50% (as a lot of P2P users are behind NAT or firewalls)

>(And for public networks, every port is "needed" if you ask the users.)

Agreed, you then get what you want ;-)