Dell PowerConnect 8100 User's Configuration Guide - Page 820

Ports operating in the manual role do not have their configuration affected by peer devices or by internal propagation of configuration. These ports have their operational mode, traffic classes, and bandwidth information specified explicitly by the operator. These ports advertise their configuration to their peer if DCBx is enabled on that port. Incompatible peer configurations are logged and counted with an error counter. The default operating mode for each port is manual. A port that is set to manual mode sets the willing bit for DCBx client TLVs to false. Manuallyconfigured ports never internally propagate or accept internal or external configuration from other ports; in other words, a manual configuration discards any automatic configuration. Manually-configured ports may notify the operator of incompatible configurations if client configuration exchange over DCBx is enabled. Manually configured ports are always operationally enabled for DCBx clients, regardless of whether DCBx is enabled. Operationally enabled means that the port reports that it is able to operate using the current configuration. A port operating in the auto-upstream role advertises a configuration, but is also willing to accept a configuration from the link-partner and propagate it internally to the auto-downstream ports, as well as receive configuration propagated internally by other auto-upstream ports. Specifically, the willing parameter is enabled on the port and the recommendation TLV is sent to the peer and processed if received locally. The first auto-upstream port to successfully accept a compatible configuration becomes the configuration source. The configuration source propagates its configuration to other autoupstream and auto-downstream ports. Only the configuration source may propagate configuration to other ports internally. Auto-upstream ports that receive internally propagated information ignore their local configuration and utilize the internally propagated information. Peer configurations received on auto-upstream ports other than the configuration source result in one of two possibilities. If the configuration is compatible with the configuration source, then the DCBx client becomes operationally active on the upstream port. If the configuration is not compatible with the configuration source, then a message is logged indicating an incompatible configuration, an error counter is incremented, and the DCBx client is operationally disabled on the port. The expectation is that the network administrator configures the upstream devices appropriately so that all such devices advertise a compatible configuration. 820 Configuring Data Center Bridging Features