Netgear XCM8806 Chassis Hardware Installation Guide - Page 739

NETGEAR 8800 Chassis Switch CLI Manual Note: If you use EMISTP or PVST+, the STPD ID must be identical to the VLAN ID of the carrier VLAN in that STPD. If you have an 802.1D configuration, NETGEAR recommends that you configure the StpdID to be identical to the VLAN ID of the carrier VLAN in that STPD. If you configure MSTP, you do not need carrier VLANs for MSTP operation. With MSTP, you configure a CIST that controls the connectivity of interconnecting MSTP regions and sends BPDUs across the regions to communicate the status of MSTP regions. All VLANs participating in the MSTP region have the same privileges. Protected VLAN Protected VLANs are all other VLANs that are members of the STPD. These VLANs "piggyback" on the carrier VLAN. Protected VLANs do not transmit or receive STP BPDUs, but they are affected by STP state changes and inherit the state of the carrier VLAN. Protected VLANs can participate in multiple STPD, but any particular port in the VLAN can belong to only one STPD. Also known as non-carrier VLANs. If you configure MSTP, all member VLANs in an MSTP region are protected VLANs. These VLANs do not transmit or receive STP BPDUs, but they are affected by STP state changes communicated by the CIST to the MSTP regions. MSTIs cannot share the same protected VLAN; however, any port in a protected VLAN can belong to multiple MSTIs. STPD Modes An STPD has three modes of operation: • 802.1D mode Use this mode for backward compatibility with previous STP versions and for compatibility with third-party switches using IEEE standard 802.1D. When configured in this mode, all rapid configuration mechanisms are disabled. • 802.1w mode Use this mode for compatibility with Rapid Spanning Tree (RSTP). When configured in this mode, all rapid configuration mechanisms are enabled. The benefit of this mode is available on point-to-point and edge ports only. You enable or disable RSTP on a per STPD basis only. You do not enable RSTP on a per port basis. • MSTP mode Use this mode for compatibility with Multiple Spanning Tree (MSTP, 802.1s). MSTP is an extension of RSTP and offers the benefit of better scaling with fast convergence. When configured in this mode, all rapid configuration mechanisms are enabled. The benefit of MSTP is available only on point-to-point links and when you configure the peer in MSTP Chapter 17. STP Commands | 739