A note to confirm that "-m physdev --physdev-is-bridged" in the iptables command does enable iptables to work in a bridged environment. I was fighting the same problem and this indeed solved it. Below is my test script running on a two NIC Debian 3.1 266MHz bridge. Before adding the physdev flag, only the "tc filter" commands worked but now the iptables commands also correctly classify the packets both with the MARK and CLASSIFY approaches. Note that the tc classes were setup to give clear indication of which class was affecting the flow. Edwin ---------test tc script---------- #!/bin/bash RATE=8000 #if [ x$1 = ''xstop'' ]; then if [ tc ]; then echo "Deleting qdisc for eth1" tc qdisc del dev eth1 root fi tc qdisc add dev eth1 root handle 1:0 htb default 90 tc class add dev eth1 parent 1:0 classid 1:1 htb rate ${RATE}kbit ceil ${RATE}kbit tc class add dev eth1 parent 1:1 classid 1:10 htb rate 3000kbit ceil 3000kbit tc class add dev eth1 parent 1:1 classid 1:20 htb rate 1500kbit ceil 1500kbit tc class add dev eth1 parent 1:1 classid 1:30 htb rate 1000kbit ceil 1000kbit tc class add dev eth1 parent 1:1 classid 1:50 htb rate 500kbit ceil 500kbit tc class add dev eth1 parent 1:1 classid 1:90 htb rate 256kbit ceil 256kbit tc qdisc add dev eth1 parent 1:10 handle 10: sfq perturb 10 tc qdisc add dev eth1 parent 1:20 handle 20: sfq perturb 10 tc qdisc add dev eth1 parent 1:30 handle 30: sfq perturb 10 tc qdisc add dev eth1 parent 1:50 handle 50: sfq perturb 10 tc qdisc add dev eth1 parent 1:90 handle 90: sfq perturb 10 #tc filter add dev eth1 parent 1:0 protocol ip u32 match ip sport 80 0xffff classid 1:10 #tc filter add dev eth1 parent 1:0 protocol ip u32 match ip sport 22 0xffff classid 1:20 #tc filter add dev eth1 parent 1:0 protocol ip u32 match ip sport 25 0xffff classid 1:50 #tc filter add dev eth1 parent 1:0 protocol ip u32 match ip sport 110 0xffff classid 1:50 iptables -F -t mangle #out #iptables -t mangle -A POSTROUTING -m physdev --physdev-is-bridged -p tcp --sport 80 -j MARK --set-mark 2 #iptables -t mangle -A FORWARD -o eth1 -p tcp --sport 22 -j MARK --set-mark 1 #iptables -t mangle -A FORWARD -o eth1 -p tcp --sport 25 -j MARK --set-mark 1 #iptables -t mangle -A FORWARD -o eth1 -p tcp --sport 110 -j MARK --set-mark 1 # iptables -t mangle -A POSTROUTING -m physdev --physdev-is-bridged -p tcp --sport 80 -j CLASSIFY --set-class 1:50 iptables -t mangle -A POSTROUTING -m physdev --physdev-is-bridged -p tcp --sport 139 -j CLASSIFY --set-class 1:10 iptables -t mangle -A POSTROUTING -m physdev --physdev-is-bridged -p tcp --sport 22 -j CLASSIFY --set-class 1:10 iptables -t mangle -A POSTROUTING -m physdev --physdev-is-bridged -p tcp --sport 25 -j CLASSIFY --set-class 1:10 iptables -t mangle -A POSTROUTING -m physdev --physdev-is-bridged -p tcp --sport 110 -j CLASSIFY --set-class 1:10 #tc filter add dev eth1 parent 1:0 protocol ip handle 1 fw classid 1:10 #tc filter add dev eth1 parent 1:0 protocol ip handle 2 fw classid 1:20 #tc filter add dev eth1 parent 1:0 protocol ip handle 3 fw classid 1:30 #tc filter add dev eth1 parent 1:0 protocol ip handle 5 fw classid 1:50 #tc filter add dev eth1 parent 1:0 protocol ip handle 9 fw classid 1:90 -- <=+=+=+==+=+=+==+=+=+=+=+=+=+=+=> Edwin Whitelaw, P.E. New River Valley Unwired, LLC 2200 Lonesome Dove Dr Christiansburg, VA 24073 540-239-0318