Multiple Instance Spanning-Tree Operation

Configuring MSTP

Syntax: [no] spanning-tree < port-list> auto-edge-port

Supports the automatic identification of edge ports. The port will look for BPDUs for 3 seconds; if there are none it begins forwarding packets. If admin-edge-portis enabled for a port, the setting for auto-edge-portis ignored whether set to yes or no. If admin-edge-portis set to No, and auto- edge-porthas not been disabled (set to No), then the auto- edge-portsetting controls the behavior of the port. (Default: Yes - enabled)

The no spanning-tree < port-list> auto-edge-port command disables auto-edge-port operation on the specified ports.

Syntax: spanning-tree < port-list> hello-time < global 1 - 10 >

When the switch is the CIST root, this parameter specifies the interval (in seconds) between periodic BPDU transmissions by the designated ports. This interval also applies to all ports in all switches downstream from each port in the < port-list>. A setting of global indicates that the ports in < port-list> on the CIST root are using the value set by the global spanning-tree hello-timevalue (page 4-23). When a given switch “X” is not the CIST root, the per-port hello-timefor all active ports on switch “X” is propagated from the CIST root, and is the same as the hello-timein use on the CIST root port in the currently active path from switch “X” to the CIST root. (That is, when switch “X” is not the CIST root, then the upstream CIST root’s port hello- time setting overrides the hello-timesetting configured on switch “X”).

(Default Per-Port setting: Use Global. Default Global Hello-Time: 2.)

Syntax: spanning-tree < port-list> mcheck

Forces a port to send RST/MST BPDUs for 3 seconds. This tests whether all STP bridges on the attached LAN have been removed and the port can migrate to native MSTP mode and use RST/MST BPDUs for transmission.

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