Dell C1048P Port Extender Networking Configuration Guide for the C9000 Series - Page 290

strict-priority scheduling (strict-priority command). The priority group for strict-priority scheduling (scheduler strict command. Configure a DCBx Operation DCB devices use data center bridging exchange protocol (DCBx) to exchange configuration information with directly connected peers using the link layer discovery protocol (LLDP) protocol. DCBx can detect the misconfiguration of a peer DCB device, and optionally, configure peer DCB devices with DCB feature settings to ensure consistent operation in a data center network. DCBx is a prerequisite for using DCB features, such as priority-based flow control (PFC) and enhanced traffic selection (ETS), to exchange link-level configurations in a converged Ethernet environment. DCBx is also deployed in topologies that support lossless operation for FCoE or iSCSI traffic. In these scenarios, all network devices are DCBx-enabled (DCBx is enabled end-to-end). • Configure Enhanced Transmission Selection DCBx supports the following versions: CIN, CEE, and IEEE2.5. DCBx is not supported on PE ports and C9010 cascade ports (member ports in the C9010 LAG created to connect to an attached C1048P). Prerequisite: For DCBx, enable LLDP on all DCB devices. DCBx Operation DCBx performs the following operations: • Discovers DCB configuration (such as PFC and ETS) in a peer device. • Detects DCB mis-configuration in a peer device; that is, when DCB features are not compatibly configured on a peer device and the local switch. Mis-configuration detection is feature-specific because some DCB features support asymmetric configuration. • Reconfigures a peer device with the DCB configuration from its configuration source if the peer device is willing to accept configuration. • Accepts the DCB configuration from a peer if a DCBx port is in "willing" mode to accept a peer's DCB settings and then internally propagates the received DCB configuration to its peer ports. DCBx Port Roles To enable the auto-configuration of DCBx-enabled ports and propagate DCB configurations learned from peer DCBx devices internally to other switch ports, use the following DCBx port roles. Auto-upstream The port advertises its own configuration to DCBx peers and is willing to receive peer configuration. The port also propagates its configuration to other ports on the switch. The first auto-upstream that is capable of receiving a peer configuration is elected as the configuration source. The elected configuration source then internally propagates the configuration to other auto-upstream and auto-downstream ports. A port that receives an internally propagated configuration overwrites its local configuration with the new parameter values. When an auto-upstream port (besides the configuration source) receives and overwrites its configuration with internally propagated information, one of the following actions is taken: 290 Data Center Bridging (DCB)