Hi, Internet---------[linux]---------network eth0 eth1 (192.168.1.103) (172.16.1.1) I can control traffic with the following: #begin ***************************** tc qdisc add dev eth1 root handle 10: cbq bandwidth 100Mbit avpkt 1000 tc class add dev eth1 parent 10:0 classid 10:1 cbq bandwidth 100Mbit \ rate 10Mbit allot 1514 weight 1Mbit prio 8 maxburst 20 avpkt 1000 tc class add dev eth1 parent 10:1 classid 10:100 cbq bandwidth 100Mbit \ rate 8Mbit allot 1514 weight 800Kbit prio 5 maxburst 20 avpkt 1000 bounded tc class add dev eth1 parent 10:1 classid 10:200 cbq bandwidth 100Mbit \ rate 2Mbit allot 1514 weight 200Kbit prio 5 maxburst 20 avpkt 1000 bounded tc qdisc add dev eth1 parent 10:100 sfq quantum 1514b perturb 15 tc qdisc add dev eth1 parent 10:200 sfq quantum 1514b perturb 15 tc filter add dev eth1 parent 10:0 protocol ip prio 25 u32 match \ ip dst 172.16.0.0/16 flowid 10:200 #end ****************************** But cannot with the following: #+++++++++++++++++++++++++++++++++++++ tc qdisc add dev eth0 root handle 12: cbq bandwidth 10Mbit avpkt 1400 tc class add dev eth0 parent 12: classid 12:1 cbq bandwidth 10Mbit rate 10Mbit allot 1514 weight 1Mbit prio 2 maxburst 20 avpkt 1400 tc class add dev eth0 parent 12:1 classid 12:212 cbq bandwidth 10Mbit rate 256Kbit allot 1514 weight 25Kbit prio 5 maxburst 20 avpkt 1400 tc class add dev eth0 parent 12:1 classid 12:213 cbq bandwidth 10Mbit rate 64Kbit allot 1514 weight 6Kbit prio 5 maxburst 20 avpkt 1400 bounded tc class add dev eth0 parent 12:1 classid 12:300 cbq bandwidth 10Mbit rate 3Mbit allot 1514 weight 300Kbit prio 3 maxburst 20 avpkt 1400 tc qdisc add dev eth0 parent 12:212 sfq quantum 1514b perturb 15 tc qdisc add dev eth0 parent 12:213 sfq quantum 1514b perturb 15 tc qdisc add dev eth0 parent 12:300 sfq quantum 1514b perturb 15 tc filter add dev eth0 parent 12:0 protocol ip prio 10 u32 match ip src 172.16.0.0/16 flowid 12:300 #+++++++++++++++++++++++++++++++++++++++++++ What wrong with the latter? Please help me. Thanks. regards, Chuanbo Xu iproute2@btamail.net.cn