AskProCurve Article

Title:

HP ProCurve Managed Switch -- Loop Protection vs. Spanning Tree Protocol

Available Part Numbers:

J4819A,J4820A,J4820B,J4821A,J4821B,J4839A,J4848A,J4848B,J4849A,J4849B,J4850A,J4852A,J4861A,J4862B,J4863A,J4864A,J4865A,J4878A,J4878B,J4887A,J4888A,J4892A,J4893A,J4899A,J4899B,J4899C,J4900A,J4900B,J4900C,J4901A,J4903A,J4904A,J4905A,J4906A,J4907A,J4908A,J8151A,J8152A,J8161A,J8162A,J8164A,J8165A,J8166A,J8167A,J8692A,J8693A,J8697A,J8698A,J8699A,J8700A,J8702A,J8705A,J8706A,J8707A,J8708A,J8712A,J8713A,J8714A,J8762A,J8763A,J8764A,J8765A,J8766A,J8768A,J8770A,J8772A,J8773A,J8775A,J8776A,J8988A,J9019A,J9019B,J9020A,J9021A,J9022A,J9030A,J9033A,J9049A,J9050A,J9064A,J9085A,J9086A,J9087A,J9088A,J9089A,J9279A,J9280A

Issue Description:

Is Loop Protection different than Spanning Tree? Can I use Loop Protection to prevent loops but without causing any computing issues among the switches or ports? Any pros or cons?

Solution:

Loop Protection can be used independently of Spanning Tree Protocol and is targeted for use on ports to which unmanaged devices are connected. Unmanaged devices will typically drop Spanning Tree BPDUs. Loop Protection serves by transmitting loop protocol packets outward from the ports on which it is enabled. Should a switch receive a loop-protocol packet back on a port for which you have set the action to “send-disable,�? then the port will be shut down.

You can configure a disable-timer parameter that will allow you to specify the amount of time you want the port to remain disabled (0 to 6048000 seconds). The default value of the “disable-timer�? parameter is “0,�? meaning that the port will not be re-enabled without manual intervention on your part.

Loop Protection should not impact end-nodes, and is not intended for ports that serve as uplinks between Spanning Tree-aware switches.

Modified Date:

2009-08-01