CIN is Cisco Intel Nuova DCBX (version 1.0). CEE is converged enhanced ethernet DCBX (version 1.06). IEEE is 802-1 az version. The default value is auto. DCBX supports the legacy implementations v1.0 (CIN) and v1.06 (CEE) in addition to standard IEEE version 2.4 DCBX. 1.DCBX starts in standard IEEE mode by sending an IEEE standard version 2.4 DCBX frame. If the peer responds, then IEEE standard version 2.4 DCBX is used,Starts means after a link up, a DCBX timeout (or multiple peer condition) or when commanded by the network operator. If DCBX receives a DCBX frame with an OUI indicating a legacy version, it immediately switches into legacy mode for the detected version and does not wait for the 3x LLDP fast timeout. 2.If no IEEE DCBX response is received within 3 times the LLDP fast transmit timeout period, DCBX immediately transmits a version 1.06 DCBX frame with the appropriate version number. If DCBX receives a DCBX frame with an OUI indicating IEEE standard support, it immediately switches into IEEE standard mode and does not wait for the timer. If DCBX receives a DCBX frame with an OUI indicating legacy mode and a version number indicating version 1.0 support, it immediately switches into legacy 1.0 mode and does not wait for the timer. 3.If no version 1.06 response is received within 3 times the DCBX fast transmit timeout period, DCBX falls back to version 1.0 and immediately transmits a version 1.0 frame. If no response is received within 3 times the DCBX fast transmit period, DCBX waits the standard LLDP timeout period, and then begins again with step 1. If DCBX receives a DCBX frame with an OUI indicating IEEE standard mode, it immediately switches into IEEE standard mode.