shapecfg - Traffic Shaper for Linux

shapecfg attach shaper-device other-device

shapecfg speed device speed

shapecfg is a program to limit bandwidth on a virtual network interface.

A shaper device is configured using the shapecfg program. Typically you will do something like this:

shapecfg attach shaper0 eth1

shapecfg speed shaper0 64000

ifconfig shaper0 myhost netmask 255.255.255.240 broadcast 1.2.3.255 up

route add -net some.network netmask a.b.c.d dev shaper0

The shaper should have the same IP address as the device it is attached to for normal use.

The shaper shapes transmitted traffic. It's rather impossible to shape received traffic except at the end (or a router) transmitting it.

Gated/routed/rwhod/mrouted all see the shaper as an additional device and will treat it as such unless patched. Note that for mrouted you can run mrouted tunnels via a traffic shaper to control bandwidth usage.

The shaper is device/route based. This makes it very easy to use with any setup BUT less flexible. You may well want to combine this patch with Mike McLagan <mmclagan@linux.org>'s patch to allow routes to be specified by source/destination pairs.

There is no "borrowing" or "sharing" scheme. This is a simple traffic limiter. I'd like to implement Van Jacobson and Sally Floyd's CBQ architecture into Linux one day (maybe in 2.1 sometime) and do this with style.

(CBQ was added to Linux in the 2.1 series. On Debian systems, see the iproute package for the necessary userspace tools. Support for the simple traffic shaper is still present as of 2.4, and, while it is less flexible, most people will probably find it easier to set up.)

More documentation can be found in /usr/share/doc/shapecfg/.

This manual page was stitched together from the original author's documentation by Christoph Lameter <christoph@lameter.com>, and added to by Colin Watson <cjwatson@debian.org>, for the Debian GNU/Linux system (but may be used by others).