Cisco WS-SUP32-GE-3B Software Configuration Guide - Page 272

Configuring MST Chapter 17 Configuring STP and MST By default, the link type is controlled from the duplex mode of the interface: a full-duplex port is considered to have a point-to-point connection; a half-duplex port is considered to have a shared connection. If you have a half-duplex link physically connected point-to-point to a single port on a remote switch running MST, you can override the default setting of the link type and enable rapid transitions to the forwarding state. To override the default link-type setting, perform this task: Step 1 Step 2 Step 3 Step 4 Step 5 Step 6 Command Router# configure terminal Router(config)# interface {{gigabitethernet 1/port} | {port-channel number}} Router(config)# spanning-tree link-type point-to-point Router(config)# end Router# show spanning-tree mst interface interface_id Router# copy running-config startup-config Purpose Enters global configuration mode. (Optional) Specifies an interface to configure, and enters interface configuration mode. Specifies that the link type of a port is point-to-point. Returns to privileged EXEC mode. Verifies your entries. (Optional) Saves your entries in the configuration file. To return the port to its default setting, use the no spanning-tree link-type interface configuration command. Designating the Neighbor Type A topology could contain both prestandard and 802.1s standard compliant devices. By default, ports can automatically detect prestandard devices, but they can still receive both standard and prestandard BPDUs. When there is a mismatch between a device and its neighbor, only the CIST runs on the interface. You can choose to set a port to send only prestandard BPDUs. The prestandard flag appears in all the show commands, even if the port is in STP compatibility mode. To override the default link-type setting, perform this task: Step 1 Step 2 Step 3 Step 4 Step 5 Step 6 Command Router# configure terminal Router(config)# interface {{gigabitethernet 1/port} | {port-channel number}} Router(config)# spanning-tree mst pre-standard Router(config)# end Router# show spanning-tree mst interface interface_id Router# copy running-config startup-config Purpose Enters global configuration mode. (Optional) Specifies an interface to configure, and enters interface configuration mode. Specifies that the port can send only prestandard BPDUs. Returns to privileged EXEC mode. Verifies your entries. (Optional) Saves your entries in the configuration file. To return the port to its default setting, use the no spanning-tree mst prestandard interface configuration command. 17-48 Catalyst Supervisor Engine 32 PISA Cisco IOS Software Configuration Guide, Release 12.2ZY OL-11439-03