ipfw pipe config bw tun0

[Luigi Rizzo]

On Sun, Jun 29, 2014 at 4:16 PM, Wojciech Puchar <
wojtek at wojtek.tensor.gdynia.pl> wrote:

> i tried to use ipfw dummynet as described in manual
>
> ---
> If a device name is specified instead of a numeric value, as in
>
>                    ipfw pipe 1 config bw tun0
>
>              then the transmit clock is supplied by the specified device.
> At
>              the moment only the tun(4) device supports this functionality,
>              for use in conjunction with ppp(8).
>
> ----
>
>
> got "no if support" error message. what i missed?
>

you missed ​nothing -- it's just that no device that i know
of still implements the feature.
i implemented it 15 years ago and enabled it on the 'ed'
device driver only.

What it needed is a notification on the transmit
interrupt to kick the pipe and tell it how many
packets went out (at the time 'ed' only supported
one packet at a time, so the code might make
assumptions).​

It might need a bit of redesign these days to make it
work efficiently with fast pipes and deep interface queues.

cheers
luigi