Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. And see here for current known issues.

New Member

QoS - dscp matching and setting not working when together


I am implementing QoS for outgoing traffic on the ATM interface of a 876 router.

I am marking certain traffic entering the LAN interface with dscp=1 to differenciate from other traffic at the output policy of the WAN interface, and then resetting the dscp to default value before going to the output queue.

The problem is that the packets marked with dscp=1 are correctly identified, but they are not getting the dscp value reset, and so they are going to the output queue still marked with dscp=1.

...Class-map: qos_dscp_1 (match-any)

......66013 packets, 5124458 bytes

......5 minute offered rate 2000 bps, drop rate 0 bps

......Match: dscp 1

........66013 packets, 5124458 bytes

........5 minute rate 2000 bps

......QoS Set

........dscp default

..........Packets marked 0


........Output Queue: Conversation 42

........Bandwidth 15 (%)

........Bandwidth 76 (kbps)Max Threshold 64 (packets)

........(pkts matched/bytes matched) 66013/5124458

........(depth/total drops/no-buffer drops) 0/0/0

If I add another match condition of type protocol match or acl match, packets matching those get the dscp reset, only packets that match the dscp condition are not getting the dscp reset.

I am running IOS 12.4(15)T1, maybe this is a bug of this release or is something I am missing?

Thanks for any help.


New Member

Re: QoS - dscp matching and setting not working when together

Hi Rui

Could you share your inteface configs and also let us know if you are using any tunnelling/other features on the router.



Super Bronze

Re: QoS - dscp matching and setting not working when together

Could you also post a config?