Until now I've been using HTB instead of CBQ and it worked quite good. I try now to prio ICMP and SSHwith the following: tc_htb qdisc add dev eth1 root handle 1: htb default 10 # total #78Kbytes tc class add dev eth1 parent 1: classid 1:1 htb rate 76kbps ceil 78kbps burst 2k #50Kbytes tc class add dev eth1 parent 1:1 classid 1:10 htb rate 48kbps ceil 76kbps burst 2k #PRIO as qdisk for this slice tc qdisc add dev eth1 parent 1:10 handle 100: prio #I try to avoid a situation where a "massive" ping would disrupt everything else tc qdisc add dev eth1 parent 100:1 handle 101 tbf rate 8kbps latency 1500ms burst 1540 #The second band (probably HTTP) shouldn't eat everything from FTP which should be tc filtered in band 3... tc qdisc add dev eth1 parent 100:2 handle 102:1 htb default 100221 tc class add dev eth1 parent 102:1 classid 1002:1 htb rate 40kbps ceil 76kbps burst 2k ... and the last line gives me an error: RTNETLINK answers: Invalid argument. Why?