Netgear XCM8810 Chassis Hardware Installation Guide - Page 762

NETGEAR 8800 Chassis Switch CLI Manual Default STP.1D ports are broadcast link types 802.1w and MSTP ports are point-to-point link types Usage Guidelines If your STPD has the same name as another component, for example a VLAN, NETGEAR recommends that you specify the identifying keyword as well as the name. If your STPD has a name unique only to that STPD, the keyword stpd is optional. The default, broadcast links, supports legacy STP (802.1D) configurations. If the switch operates in 802.1D mode, any configured port link type will behave the same as the broadcast link type. RSTP rapidly moves the designated ports of a point-to-point link type into the forwarding state. This behavior is supported by RSTP and MSTP only. In an MSTP environment, configure the same link types for the CIST and all MSTIs. Auto Link Type An auto link behaves like a point-to-point link if the link is in full duplex mode or if link aggregation is enabled on the port; otherwise, an auto link behaves like a broadcast link. If a non-STP switch exists between several switches operating in 802.1w mode with auto links, the non-STP switch may negotiate full-duplex even though the broadcast domain extends over several STP devices. Edge Link Type RSTP does not send any BPDUs from an edge port nor does it generate topology change events when an edge port changes its state. If you configure a port to be an edge port, the port immediately enters the forwarding state. Edge ports remain in the forwarding state unless the port receives a BPDU. In that case, edge ports enter the blocking state. The edge port remains in the blocking state until it stops receiving BPDUs and the message age timer expires. Edge Safeguard Loop prevention and detection on an edge port configured for RSTP or MSTP is called edge safeguard. You configure edge safeguard on RSTP or MSTP edge ports to prevent accidental or deliberate misconfigurations (loops) resulting from connecting two edge ports together or by connecting a hub or other non-STP switch to an edge port. Edge safeguard also limits the impact of broadcast storms that might occur on edge ports. An edge port configured with edge safeguard immediately enters the forwarding state and transmits BPDUs. This advanced loop prevention mechanism improves network resiliency but does not interfere with the rapid convergence of edge ports. Recovery time starts as soon as the port becomes disabled. If no recovery-timeout is specified, the port is permanently disabled. 762 | Chapter 17. STP Commands