Re: freebsd's dummynet or selectable traffic shaping

Andi Kleen (
Sun, 6 Dec 1998 20:55:08 +0100

On Sun, Dec 06, 1998 at 08:30:00PM +0100, Chris Evans wrote:
> On Sun, 6 Dec 1998, Andi Kleen wrote:
> > Another alternative is the queueing framework in 2.1, which has modules
> > for traffic shaping, classifying packets etc. (see linux/net/sched/*.c)
> Hi Andy!
> Sorry to trouble you. The new traffic queuing stuff in 2.1 is probably the
> most "myserious" new feature to me. Is there anywhere with details of
> functionality provided?

Only the source code so far (the modules in net/sched/*.c carry comments
that describe their use)

> Can the new stuff do
> a) Prioritize packets of my choice, e.g. place all port 23 traffic at the
> head of the transmit queue?

Yes. You can hand out markings per packet using firewall rules or
routes or the cls_u32 qualifier and the various queueing modules can
prioritize according to them. Actually simply prioritizing was possible
in 2.0 too - it queues per default based on the IP type-of-service field.

> b) Limit all traffic destined to e.g. 123.123.x.x to 100kbytes/sec?

Yes. Was possible in 2.0 using the shaper device, in 2.1 you can do
it by applying a token bucket filter to a particular class (or using
the CBQ module)

To configure all these features you need iproute2 from


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