Re: altq filter acts before or after npf NAPT?

[Rocky Hotas <rockyhotas%firemail.cc@localhost>]

On ott 23 15:47, BERTRAND Joël wrote:
> and altqd runs as expected. Only a few bugs. Don't try to launch
> /etc/rc.d/altqd reload, altqd will take 100% of a CPU. Don't try to stop
> altqd, you will obtain a kernel panic.

Some updates: if altqd.conf has only a queing discipline per each
interface, I can (with 9.0 release) do `service altqd stop', `service
altqd start' with no issues.

If altqd.conf contains only a traffic conditioner for a single interface,
it is impossibile to stop altqd. `service altqd stop' does have no
effect: shell hangs in `sleep' mode; a Ctrl+C will restore the shell, but
altqd will still be running (however, `altqstat' does not show anything,
so maybe altqd is not fully functional).
Most important thing: a `shutdown' will not be able to stop `altqd'. It
blocks here:

System shutdown time has arrived

About to run shutdown hooks...
Stopping cron.
Stopping inetd.
Stopping altqd.

Another important introduction to altq, if anyone is interested, is:

 <https://www.usenix.org/legacy/event/usenix99/full_papers/cho/cho.pdf>

``Managing Traffic with ALTQ'', from Kenjiro Cho, published in 1999

A couple of observations:
- ``An interface can have one queueing discipline attached at a time''
  (par. 3.1.2), so it's not possible to define multiple queueing
  disciplines for the same network interface.
- Maybe the issues regarding the kernel timer resolution, assumed to be
``10msec in most UNIX system'' (par. 3.2.1), are outdated.

Bye!

Rocky