810 Configuring Data Center Bridging Featuresthe willing parameter is disabled on auto-downstream. By default, auto-downstream ports have the recommendation TLV parameter enabled. Auto-downstream ports that receive internally propagated information ignore theirlocal configuration and utilize the internally propagated information. Auto-downstream ports propagate PFC, ETS, and application priority informationreceived from the configuration source.In the Configuration Source role, the port has been manually selected to bethe configuration source. Configuration received over this port is propagatedto the other auto configuration ports, however, no automatic election of anew configuration source port is allowed. Events that cause selection of a newconfiguration source are ignored. The configuration received over theconfiguration source port is maintained until cleared by the operator (set theport to the manual role).Configuration Source Port Selection ProcessWhen an auto-upstream or auto-downstream port receives a configurationfrom a peer, the DCBx client first checks if there is an active configurationsource. If there is a configuration source already selected, the receivedconfiguration is checked against the local port operational values as receivedfrom the configuration source, and if compatible, the client marks the port asoperationally enabled. If the configuration received from the peer isdetermined to not be compatible, a message is logged, an error counter isincremented and the DCBx clients become operationally disabled on theport. Operationally disabled means that FIP snooping and PFC will notoperate over the port. The port continues to keep link up and exchangesDCBx packets. If a compatible configuration is later received, the DCBxclients will become operationally enabled.If there is no configuration source, a port may elect itself as the configurationsource on a first-come, first-serve basis from the set of eligible ports. A port iseligible to become the configuration source if the following conditions aretrue:• No other port is the configuration source.• The port role is auto-upstream.• The port is enabled with link up and DCBx enabled.• The port has negotiated a DCBx relationship with the partner.
