Hi,

I am using Netem to simulate network conditions. I use tc to rate control traffic to a specific ip address.

I referred to the below source : http://lartc.org/howto/lartc.ratelimit.single.html to try out the same.

I used the following commands to rate control traffic to specific links

tc qdisc add dev eth0 root handle 1: cbq avpkt 1000 bandwidth 100mbit

tc class add dev $DEV parent 1: classid 1:1 cbq rate 500kbit \
allot 1500 prio 5 bounded isolated

tc filter add dev $DEV parent 1: protocol ip prio 16 u32 \
match ip dst 195.96.96.97 flowid 1:1

tc class add dev $DEV parent 1: classid 1:2 cbq rate 300kbit \
allot 1500 prio 5 bounded isolated

tc filter add dev $DEV parent 1: protocol ip prio 16 u32 \
match ip dst 195.96.96.98 flowid 1:2


Without these tc settings on my router, using iperf I get a throughput of 90Mbps. After I set the above commands, my measured throughput with iperf drops around 17Mbps as opposed to expected values of 500kbps. Similar pattern is observed on teh second link too.

I can see that CBQ settings control the throughput but does not give me the expected value. I am not sure what is wrong. Can someone help and give me some insights about this issue? Thanks

Hi, I'm not familiar to cbq. but if you just want some traffic control function, you can try htb which will make your life easier.

Thanks davyherds. yeah, htb is easier to use, but my requirement is to control bandwidth for separate flows for specific ip addresses.