Very Computer

Hi,

I'm in urgent need of help with 'Quality of Service' facilities of iproute2 -
specifically the tc command. I have been trying to set up a linux box
with 2 NICs to act as a bandwidth throttling router.  This is urgently
required for work to test bandwidth functionality but I've been
running inot problems

The router is up and running fine but I cannot get the tc command to work.
I always seem to get the same errors. I've been esperimenting with
differnet commands but my first attempt - see example - is copied out  
of the iproute2 HOWTO:

./tc class add dev eth0 parent 10:0 classid 10:1 cbq bandwidth \
10Mbit rate 10Mbit allot 1514 weight 1Mbit prio 8 maxburst 20 avpkt 1000

./tc class add dev eth0 parent 10:1 classid 10:100 cbq bandwidth 10Mbit \
rate 1Mbit allot 1514 weight 800Kbit prio 5 maxburst 20 avpkt 1000  bounded

./tc qdisc add dev eth0 parent 10:100 sfq quantum 1514b perturb 15

./tc filter add dev eth0 parent 10:0 protocol ip prio 100 u32 match ip \
dst 172.16.0.0/16 flowid 10:100

and generates:

RTNETLINK answers: No such file or directory
RTNETLINK answers: No such file or directory
RTNETLINK answers: No such file or directory
RTNETLINK answers: Invalid argument

I first tried the with the standard Mandrake 2.2.4-15 kernel - and the
latest rpm download of iproutes2. Next I donwloaded the iproute2
'patches' for the kernel and recompiled - also downloading the latest
sources for iproute2 and patching those. Finally, I have tried compiling
the latest 2.4 kernel with all the appropraite modules as requested in
most documentation - I have even tried compiling in (rather than loading
moduled) nearly any network related function I can find that could possibly
be linked - but still I get the same errors. Whether they are being
generated by the same problem I don't know (I have seen documentation
saying that there are very limited error messaging for tc). It must
be something else I'm doing - or haven't done.

I'm going to try 'shaper' Sunday - just in case - but it looks as if
it will only run when modularized (and I compiled it straight in the last kernel
build) so its Sunday in the office too :-( )

Any thoughts, possible tests, suggestions on getting to the bottom of
this will be very greatfully received. Also, any pointers to other forums to
try would be helpful.

Many thanks

Steve C

Steve, you have not created a root cbq qdisc to add the classes to.

you need something like:
tc qdisc add dev eth0 root handle 10: cbq bandwidth 10Mbit avpkt 1000
as the first line. This creates a cbq qdisc and also a cbq class.
Otherwise, you are trying to attach classes to nothing! hope this
helps. (this will create the 10:0 class that you are trying to add classes to).

Andrew King.