Dell C1048P Port Extender Networking Configuration Guide for the C9000 Series - Page 284

peer devices. PFC allows network administrators to create zero-loss links for SAN traffic that requires nodrop service, while at the same time retaining packet-drop congestion management for LAN traffic. On the switch, PFC is enabled on Ethernet ports (pfc mode on command). You can configure PFC parameters using a DCB map or the pfc priority command in Interface configuration mode. For more information, see Configuring Priority-Based Flow Control. As soon as you apply a DCB map with PFC enabled on an interface, DCBx starts exchanging information with a peer. The IEEE802.1Qbb, CEE and CIN versions of PFC TLV are supported. DCBx also validates PFC configurations that are received in TLVs from peer devices. By applying a DCB map with PFC enabled, you enable PFC operations on ingress port traffic. To achieve complete lossless handling of traffic, configure PFC priorities on all DCB egress ports. NOTE: DCB maps are supported only on physical Ethernet interfaces. • To remove a DCB map, including the PFC configuration it contains, use the no dcb map command in Interface configuration mode. • To disable PFC operation on an interface, use the no pfc mode on command in DCB-Map configuration mode. • Traffic may be interrupted when you reconfigure PFC no-drop priorities in a DCB map or re-apply the DCB map to an interface. • For PFC to be applied, the configured priority traffic must be supported by a PFC peer (as detected by DCBx). • If you apply a DCB map with PFC disabled (pfc off), you can enable link-level flow control on the interface using the flowcontrol rx on tx on command. To delete the DCB map, first disable link-level flow control. PFC is then automatically enabled on the interface because an interface is PFC-enabled by default, when DCB is enabled. • To ensure no-drop handling of lossless traffic, PFC allows you to configure lossless queues on a port (see Configuring Lossless Queues). • When you configure a DCB map with more than the maximum lossless queues configured, an error message is displayed if the PFC dot1p priorities result in more than two lossless queues. • When you apply a DCB map, an error message is displayed if link-level flow control is already enabled on an interface. You cannot enable PFC and link-level flow control at the same time on an interface. • Configure all the backplane ports of the linecards and RPM0 and RPM1 with same dcb-map configuration. dcb-map linecard 0 backplane all name dcb-map linecard all backplane all name • Dell Networking OS allows you to change the default dot1p priority-queue assignments only if the change satisfies the following requirements in DCB maps already applied to the interfaces: - All 802.1p priorities mapped to the same queue must be in the same priority group. - A maximum of four PFC-enabled, lossless queues are supported on an interface. Otherwise, the reconfiguration of a default dot1p-queue assignment is rejected. • To ensure complete no-drop service, apply the same PFC parameters on all PFC-enabled peers. ETS Configuration Notes ETS provides a way to optimize bandwidth allocation to outbound 802.1p classes of converged Ethernet traffic. Different traffic types have different service needs. Using ETS, you can create groups within an 284 Data Center Bridging (DCB)