dot1q-tunnel cos mapping

[markausten]

Is it possible to map the cos from a tagged frame into the metro tag cos field when it enters a dot1q-tunnel port?

The only option I see to set cos on a dot1q-tunnel port is to statically configure a value using the <mls qos cos <value> > commmand, this is with the 3750.

Thanks

[tphelps]

It's been a while since I've looked for sure but check out the "mls qos trust cos" command.

http://www.cisco.com/en/US/products/hw/switches/ps5023/products_tech_note09186a0080883f9e.shtml#cg211

[markausten]

The problem I am seeing is the cos is not copied to the metro tag cos field when a tagged frame enters a dot1q-tunnel port. I think this is due to the dot1-tunnel port behaviour of treating any traffic on a tunnel port as untagged even if it is tagged. I've tried trusting cos on the interface and it's still marked as 0.

Thanks

[Pavel Bykov · Accepted solution]

It all depends on the hardware.

For example 3750 Metro support copying inner CoS value to the outer tag. It is also supported by 4500s with SUPV-10GE.

Also this functionality is possible with ES20 cards in 7600.

Overall there is not much hardware that support it. The functionality you are looking for is called "ntelligent IEEE 802.1Q tunneling QoS"

http://www.cisco.com/en/US/docs/switches/metro/catalyst3750m/software/release/12.2_25_seg_seg1/configuration/guide/swtunnel.html#wp1010491