Kazaa/p2p on a LAN and ping problems

[Alex de Kruijff]

On Thu, Nov 27, 2003 at 07:49:07PM -0600, Eric Timme wrote:
> Network topology:
> 
> LAN <==> FreeBSD Gateway <==> Internet
> 
> Gateway specifications:
> FreeBSD overlord 4.8-STABLE FreeBSD 4.8-STABLE #0: Mon Sep 22 07:05:09 CDT 
> 2003
> k6-233, 128MB ram
> ipf packet filtering in place
> 
> Internet (cable):
> 256kb up
> 2.0mbish down
> 
> ======
> 
> It seems an impossible task to limit Kazaa and other p2p (Kazaa especially) 
> from accessing the Internet from a LAN, especially when you're sharing the 
> LAN with other college age people. So, I've instead told them to limit their 
> upstream to 5kB, which leaves a good amount of of the upstream pipe for web 
> browsing.
> 
> However, whenever any p2p in the house is active pings on any external network 
> degrade horribly, even if it's only a single host, and 20kb of my upstream 
> bandwith remains. 
> 
> Wolfenstein servers that I pinged 30 on with no p2p activity on the LAN, for 
> instance, begin to ping at 400-500 ; the situation is equally bad with MUDs 
> and other ping reliant games such as Quake.
> 
> Is this normal? Is there anything I can do to fix the problem so that ping 
> dependant games can be played while p2p apps are active on the LAN? Kicking 
> the network cable out works late at night, and at times during the day, but 
> it isn't a permanent solution. Limiting p2p from the LAN completely is not 
> possible from my position.
> 
> A user on IRC mentioned he had no such problem with IPFW - if my problem isn't 
> specific does that mean that my use of ipf is responsible for this behavior?

You could check if you router slots are free. They proberbly are.

You could enfore a bandwith policy on you users. You could have a static
bandwith limitation with ipfw meaning that they can only have 25% or a
dynamic one maning they have 100% unleass they use it heavly 25%.
(meaning lag when someone just starts using p2p). I have written some
article about this on my website. I integrated the ipfw firewall
options.

-- 
Alex

Articles based on solutions that I use:
http://www.kruijff.org/alex/index.php?dir=docs/FreeBSD/