Changing the QoS for a given flow

["Kaustubh S. Phanse" <kphanse@xxxxxx>]

Title: Message

Hi everyone,

 

    I am trying to set-up a scenario wherein a given traffic flow gets certain QoS to begin with, and then is moved to another QoS class. Using Linux RH7.0 kernel 2.2.16. I tried doing this using the "tc filter change" and "tc filter replace" commands, but both don't seem to work. An example scenario is as follows:

 

***** Initial set-up ****

 

tc qdisc add dev eth0 handle 1:0 root htb default 1 r2q 1
tc class add dev eth0 parent 1:0 classid 1:1 htb rate \
 64kbit ceil 64kbit burst 2k
tc qdisc add dev eth0 parent 1:1 handle 2:0 dsmark indices 64
tc class change dev eth0 classid 2:1 dsmark mask 0x3 value 0x68

 

tc class change dev eth0 classid 2:2 dsmark mask 0x3 value 0x48

 

tc filter add dev eth0 parent 2:0 protocol ip prio 1 handle 1: \
 u32 divisor 1

 

tc filter add dev eth0 parent 2:0 prio 1 u32 \
 match ip src 10.0.41.2
 match ip protocol 17 0xff
 match ip dport 5000 0xffff
 flowid 2:1

 

As shown above, initially the flow is marked with DSCP value 0x68 (confirmed using ethereal). Later, I need to move this flow to class 2:2, so that it gets marked with value 0x48. Using, "tc filter replace" to now classify the flow as 2:2 doesn't work, as the packets are still marked as 0x68. Doing "tc filter show dev eth0" returns nothing! I am not sure what I am doing wrong. Any help in this matter is appreciated.

 

Thanking in advance.

regards

Kaustubh