[TriLUG] throttling bandwidth in a test environment

[Aaron S. Joyner]

Dan Monjar wrote:

>
> Anyone know of any techniques to throttle bandwidth on a LAN for 
> testing? We want to see how an application would run across a WAN of 
> varying bandwidth.  How would I make a Ethernet segment throttle down 
> to something like T1 speeds?
>
Most of the firewalling implementations these days have the ability to 
do this.  The most flexible and powerful (and ironically also the 
simplest), is OpenBSD's "pf" firewall.  Another perfectly serviceable 
implementation is FreeBSD's ipfw2 - which is as capable as "pf" for 90% 
of things, just not quite as intuitive to configure (it's more like 
iptables than pf).

Then, there's iptables under Linux.  In order to to traffic shaping you 
need to couple iptables with another tool to handle the traffic 
shaping.  I have no practical experience with this, although a cursory 
bit of research shows that it should be possible with tc or tcng.  
Perhaps someone can provide some insight into other possible ways to 
accomplish traffic shaping under Linux.  The last time I looked at doing 
it with Linux was easily 2+ years ago, and I'm sure many developments to 
the available tools have been made since then.

Aaron S. Joyner