Configuring Data Center Bridging Features 831
console(config-if)#switchport mode trunk
5
Exit interface configuration mode for the range of interfaces.
6
Enter interface configuration mode for the CNA-facing ports and 
configure the DCBx port role as auto-downstream. This step automatically 
enables PFC on the ports.
console(config)#interface te1/0/1-3,te2/0/1-3
console(config-if)#lldp dcbx port-role auto-down
console(config-if#exit
7
Enter Interface Configuration mode for the ports connect to an FCF on 
both switches in the stack to configure the DCBx port role as auto-
upstream. 
console(config)#interface te1/0/16-17,te2/0/16-17
console(config-if)#lldp dcbx port-role auto-up
8
Set the FIP snooping port mode as 
fcf
 to indicate that these ports are 
connected to a Fibre Channel forwarder.
console(config-if)#fip-snooping port-mode fcf
console(config-if)#exit
9
Optionally, use the FIP snooping show commands to verify the 
configuration, view FIP snooping sessions, and view information about the 
ports that are connected to end nodes or FCFs.
Enhanced Transmission Selection
Networks classify and prioritize traffic to provide different service 
characteristics to end user traffic flows. Administrators may wish to guarantee 
or limit bandwidth for certain traffic, ensure lossless behavior for other traffic, 
and control the queue discipline/drop characteristics for best-effort traffic. 
Additionally, it is desirable for a switch to support sharing bandwidth among 
bursty sources while still enabling prioritization of time-sensitive or 
management traffic that requires minimum latency.
Enhanced transmission selection (ETS) provides uniform management for 
sharing bandwidth between congestion managed and traditional classes on a 
single bridged network. Using priority-based processing and weight 
allocations, Traffic Class Groups (TCGs) carrying different types of traffic 
such as LAN, SAN, and management traffic can be configured to provide 
minimum bandwidth guarantees, unused bandwidth sharing, and lossless or