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5. Apply the DCB map, created to disable the PFC operation, on the interface.
INTERFACE mode
dcb-map {name | default}
6. Configure the port queues that still function as no-drop queues for lossless traffic.You cannot configure PFC no-drop queues
on an interface on which a DCB map with PFC enabled has been applied, or which is already configured for PFC using the
pfc priority command.The maximum number of lossless queues globally supported on a port is 2.Range: 0-3. Separate
queue values with a comma; specify a priority range with a dash; for example: pfc no-drop queues 1,3 or pfc no-drop queues
2-3 Default: No lossless queues are configured.
INTERFACE mode
pfc no-drop queuesqueue-range
Data Center Bridging Exchange Protocol (DCBx)
DCBx allows a switch to automatically discover DCB-enabled peers and exchange configuration information. PFC and ETS use
DCBx to exchange and negotiate parameters with peer devices. DCBx capabilities include:
● Discovery of DCB capabilities on peer-device connections.
● Determination of possible mismatch in DCB configuration on a peer link.
●
Configuration of a peer device over a DCB link.
DCBx requires the link layer discovery protocol (LLDP) to provide the path to exchange DCB parameters with peer devices.
Exchanged parameters are sent in organizationally specific TLVs in LLDP data units. For more information, refer to Link Layer
Discovery Protocol (LLDP). The following LLDP TLVs are supported for DCB parameter exchange:
PFC parameters
PFC Configuration TLV and Application Priority Configuration TLV.
ETS parameters ETS Configuration TLV and ETS Recommendation TLV.
Data Center Bridging in a Traffic Flow
The following figure shows how DCB handles a traffic flow on an interface.
Figure 141. DCB PFC and ETS Traffic Handling
FC Flex IO Modules
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