23/11/2001 : This page is not valid. Plz go to docum.org 

RTNETLINK problem

When you get a problem about this, make sure you enabled all QOS stuff in the kernel. Compile everything in the kernel or when you use modules, make sure they are all loaded.
You can find my configuration here. Make sure that you enabed Networking options->Kernel/User netlink socket.

Possible errors:

• RTNETLINK answer: No such file or directory: handle does not exists
• RTNETLINK answer: File exists: handle already in use
• RTNETLINK answer: Invalid argument: Something else went wrong

CBQ is not very accurate to bound the traffic

When you have a bounded class, the traffic is bounded but not allways with the same accuracy (see bounded accuracy). You will have to try with some rates to found the best one.

CBQ: borrowing between classes.

You can borrow the traffic between classes. For this, you create a bounded class with rate equal to the sum of the total rate the classes may get together. After that, you create child clases with this class as parent (make the child classes not isolated ! !). Now the classes can borrow bandwidth from each other.

CBQ: dividing in different classes.

The best solution is to provide a weight parameter proportional to the rate and attch a filter to the qdisc that puts the traffic directly in the class. I have an overview about what happens with the traffic when you have different setups. You can find it here.

CBQ: You need to attach a filter to each qdisc you use to put the traffic in the right class

Each qdiscs needs his own filters to put the traffic in his classes. Here are some tests to prove it.

CBQ : the isolated parameter is not working.

When you use the isolated parameter, you get some strange results. I tried it a few times: classes tests and each time the results were very strange.

CBQ : bandwidth parameter.

The bandwidth of the root qdisd is the device bandwidth. This is 10mbit for a 10 megabit NIC and 100mbit for a 100 megabit NIC. For the subclasses, the bandwidth is equal to the bandwidth of the qdisc where the class belongs to. If you define a qdisc that's attached to a class, the bandwidth is equal to the rate of that class.

You can't attach classes to a TBF qdisc.

TBF is classless. But you can use TBF to bound the traffic of a CBQ class. You have to attch a TBF qdisc to the class you want to bound. This can also be done with the bounded option from CBQ.