qos class-map marking issue

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Guest

qos class-map marking issue

Post by Guest » Wed Dec 08, 2010 4:46 pm

Hello expert, I have a hub and spoke enviroment using all cisco 2811 routers.I am currently working on qos.I have apply class -maps and policy-map  on one router close to the source as per best practice.I went to second router and configure qos, i tried to use class-map match dscp21 etc ---- since i do not want to remark packetspreviously marked at the source.The problem is that when i check the second router using the sh policy-map int I am only see all the packets being queued under class-defaultwhich suggest that the match dscp21 etc is not working. Is there a something missing do i have to issue some command etc to allow the other sister routers to trust the orginal marking. Attached are two file for clarification Regards

Guest

Re:qos class-map marking issue

Post by Guest » Wed Dec 08, 2010 5:17 pm

A couple of things to keep in mind. 1. Packets are only placed into your configured queues when the tx ring is full. If the interface is not congested packets will not go into the queues you have setup, they will go into the default queue. 2. It looks like your applying QoS to an internet link. If so, keep in mind that some Service Providers strip the CoS values from your packets. Hope it helps.

Guest

Re:qos class-map marking issue

Post by Guest » Wed Dec 08, 2010 6:38 pm

Hello Collin, >> Packets are only placed into your configured queues when the tx ring is full. If the interface is not congested packets will not go into the queues you have setup, they will go into the default queue While awaiting your response I  removed the class mappings as per attactment and created new class mappings. And the respective queues where populated as per mapping See attachment. >> It looks like your applying QoS to an internet link. If so, keep in mind that some Service Providers strip the CoS values from your packets. Sorry for the misleading naming of the policy-map this policy is actual link to the lan interface of the second router as the aim is just see if the mapping created on Router1 will remain the same when they hit Router 2. I am trying to let one Router do all the inpection and marking of the packets and the other routers just accept the mark packets. Regards

Guest

Re:qos class-map marking issue

Post by Guest » Wed Dec 08, 2010 7:59 pm

If you are marking on router 1 and router 2s Ethernet is in the path of that marked traffic it should show up and match your policy coming into router 2, but It doesn appear to. my first guess is that your LAN switch is remarking it. If your LAN switch is a 2950 or a 2960/3560/3750 with qos enabled you will have to make sure the ports you have your routers attached to are set to trust dscp on the switch.

Guest

Re:qos class-map marking issue

Post by Guest » Wed Dec 08, 2010 8:25 pm

Hello Colin, My Lan switch may be the problem I have 2960 series at all locations. But did not set the respective ports that the router is connected to trust dscp. Colin, if i do not want to trouble my switch will I have to  setup  class markings on all my routers? Regards Jomo

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