Multiple Instance Spanning-Tree Operation

802.1s Multiple Spanning Tree Protocol (MSTP)

Configuring Loop Protection

You can use BPDU protection for systems that have spanning tree enabled (See “Configuring BPDU Protection” on page 5-27),however, the BPDU protection feature cannot detect the formation of loops when an unmanaged device on the network drops spanning tree packets. To protect against the formation of loops in these cases, you can enable the Loop Protection feature, which provides protection by transmitting loop protocol packets out ports on which loop protection has been enabled. When the switch sends out a loop protocol packet and then receives the same packet on a port that has send- disable configured, it shuts down the port from which the packet was sent.

You can configure the disable-timerparameter for the amount of time you want the port to remain disabled (0 to 604800 seconds). If you configure a value of zero, the port will not be re-enabled.

To enable loop protection, enter this command:

ProCurve(config)# loop-protect <port-list>

Syntax: [no] loop-protect <port-list> [receiver-action <send-disable no-disable> ]

[transmit-interval <1-10> ] [disable-timer <0-604800>] [trap <loop-detected>]

Allows you to configure per-port loop protection on the switch.

[receiver-action <send-disable no-disable>]

Sets the action to be taken when a loop is detected on the port. The port that received the loop protection packet determines what action is taken. If send-disable is configured, the port that transmitted the packet is disabled. If no-disable is con- figured, the port is not disabled.

Default: send-disable

[trap <loop-detected>]

Allows you to configure loop protection traps The “loop- detected” trap indicates that a loop was detected on a port.

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