I am not sure about trusting both values on the same interface - it is probably better to do this on a case-by-case basis? Mark those ports which require CoS to be trusted as such and then those that require DSCP with that.
I am pretty sure that both commands are exclusive of each other - you can either trust one or the other, not both at the same time. This allows the switch to determine which queue to place the traffic in, or whether to manipulate the marking in anyway based on one of the values. You can use Cos-to-DSCP maps to help mark the CoS traffic with the correct DSCP values and vica-versa, ensuring that you have valid QoS marking poulicy all the way through the network, regardless of whether your equipment supports Cos or DSCP (or both).
As Jonathan mentioned, you can't trust both COS/DSCP on one port. The later entered command will over write the previous one.
One solution of trusting both is to disable DSCP rewrite on the switch, and trust COS on the trunk port. That way, incoming frame with COS will be trusted, and the origin DSCP bits will be reserved. On the access port, just trust DSCP.
This is actually a pretty cool feature, i didn't even know it existed until I was looking for a solution to advertise a subnet (prefix in BGP talk), only if a certain condition existed. This is exactly what conditional advertisements does
j ai une question j ai achete un routeur cisco 887VA-k9 , je le configuré avec la configuration ci- dessous
si je le lier avec mon pc portable sur l un de ses ports directement ça marche toute est bien ( la connexion internet + m...
Attached policy provides CLI access to the Cisco 4G router over text messaging. Two files are in the attached .tar file:
2. PDF with instructions on how to load and use the .tcl file.