cos and qos

Unanswered Question
Apr 18th, 2008
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Hi all

when performing cos and qos, if I have a router connected to my switch, my switch has marked the cos value, on the exit port of the switch and entry port to the router, what do I need to do, will the router map the layer 2 802.1p value and write this into the layer 3 value? and what if the traffic travels from the router back to the switch, will it mark the layer 2 value back in so the switch can understand?

please explain

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jamesfang98 Thu, 04/24/2008 - 10:20
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In sw, cos-dscp and dscp-cos map setup will help you to achieve the goal.

IP Traffic from router end embedded either 'ip precedence' or 'dscp' in its header to indicate its own QoS tag, in switch end you need to map them to CoS to traverse LAN properly.


carl_townshend Wed, 06/18/2008 - 12:31
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so if the switch maps them, will it apply the layer 2 and layer 4 tags ?

jamesfang98 Thu, 06/26/2008 - 04:56
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A: Layer2 tags

And more, switch will generate its internal layer3 tag using cos-2-dscp for all inter-LAN traverse traffic like: via-trunk


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