HP 6120G/XG HP ProCurve Series 6120 Blade Switches Advanced Traffic Management - Page 107

Note Multiple Instance Spanning-Tree Operation Overview Overview The switches covered in this guide, use the IEEE 802.1s Multiple Spanning Tree Protocol (MSTP) standard. MSTP Features 802.1s Spanning Tree Protocol Default Setting Viewing MSTP Status and Configuration n/a Configuring MSTP Operation Mode and Disabled Global Parameters Configuring Basic Port Connectivity Parameters admin-edge-port: No-disabled auto-edge-port: Yes-enabled bpdu-filter: No-disabled bpdu-protection: No-disabled hello-time: 2 path-cost: auto point-to-point MAC: Force-True priority: 128 (multiplier: 8) root-guard: No-disabled tcn-guard: No-disabled loop protection: Send disable Configuring MSTP Instance Parameters instance (MSTPI): none priority: 32768 (multiplier: 8) Configuring MSTP Instance Per-Port Parameters path-cost: auto priority: 128 (multiplier: 8) Enabling/Disabling MSTP Spanning Tree Disabled Operation Enabling an Entire MST Region at Once n/a Page Ref page 4-49 page 4-21 and following page 4-26 and following page 4-35 page 4-37 page 4-40 page 4-40 Without spanning tree, having more than one active path between a pair of nodes causes loops in the network, which can result in duplication of messages, leading to a "broadcast storm" that can bring down the network. MSTP cannot protect against loops when there is an unmanaged device on the network that drops spanning tree packets, or may fail to detect loops where this is an edge port configured with client authentication (802.1X, Web and MAC authentication). To protect against the formation of loops in these cases, you can use the loop protection feature (see "Loop Protection" on page 4-70). 4-3