[ale] Ethernet bandwidth choker

Michael Still stillwaxin at gmail.com
Wed Dec 8 07:59:06 EST 2004


On Wed, 8 Dec 2004 06:45:41 -0500, David Corbin <dcorbin at enttek.com> wrote:
> I need a device that I can use to simulate low-bandwidth between two ethernet
> machines.  Ideally,  the box would have some limited interface to enter in  a
> desired bandwidth to simulate.  Something that works in increments of 64kbs
> would be fine.
> 
> 1) Is there a correct name for such a product.
> 2) Any recommendations?
> 
You can do this with rate limiting between ethernet interfaces I
believe.  Here's an example you can play with:

tc qdisc add dev eth0 root handle 1: cbq avpkt 1000 bandwidth 100mbit

tc class add dev eth0 parent 1: classid 1:1 cbq rate 64kbit allot 1500
prio 5 bounded isolated

tc filter add dev eth0 parent 1: protocol ip prio 16 u32 match ip dst
0.0.0.0/0 flowid 1:1

It has been my experience that the limiting is not exactly at 64kbits
(or it might be a problem at higher limits) so you might have to
change it to get it to work at the right speed.  Once you do find the
right limit, it does stay under it.  Also this only affects outbound
traffic, but you can make it affect inbound with more tc filter rules.
If the interface on the sending side is rate limited though, then I
wouldn't mess with the inbound limit.



More information about the Ale mailing list