Hi, I found that if I do this: tc qdisc add dev eth0 root handle 1: cbq bandwidth 10Mbit allot 1514 avpkt 1514 tc filter add dev eth0 parent 1:0 protocol ip prio 1 u32 match ip dst 192.168.1.0/24 flowid 1:0 everything works ok, I can direct packets to the parent flow without any problem. But if I make a subclass, I can not direct to parent anymore, only to his children. tc qdisc add dev eth0 root handle 1: cbq bandwidth 10Mbit allot 1514 avpkt 1514 tc class add dev eth0 parent 1:0 classid 1:1 cbq bandwidth 56kbit avpkt 1514 rate 56kbit allot 1514 maxburst 5 prio 5 bounded isolated tc filter add dev eth0 parent 1:0 protocol ip prio 1 u32 match ip dst 192.168.1.0/24 flowid 1:0 as shows this example, if I direct to the parent when it has children, the kernel cycles forever in cbq_classify() function in the for (;;) loop. The question is, is it a bug or I just don''t understand CBQ''s idea? Can I direct packets to the parent when it has children? Thanks in advance Nikolai