[c-nsp] PFC QOS question about 802.1Q trunks

Matthew Huff mhuff at ox.com
Tue May 19 12:20:19 EDT 2009

I have a question about QOS trust between two 6509 switches connected via a L2 802.1Q trunk with multiple VLANs. If the port is set to "trust cos", what does the internal DSCP value get set for native frames since their isn't a COS field? I would assume the internal DSCP value would be set to the default or normally zero. Do most people then set the native VLAN to a unused VLAN so that native packets have internal DSCP values set? Or do most use "trust dscp"? If so, what do people use "trust cos" for?

Matthew Huff       | One Manhattanville Rd
OTA Management LLC | Purchase, NY 10577
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