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switch: spanning tree

I have three switches:

Switch A, 5509

Switch B, 5505

Switch C, 3548

Switch A is connected to switch B and C

Switch B is connected to switch A and C

Switch C is connected to switch A and B

None of them is the root switch.

The state of spanning tree is this:

A(forwarding)-B(Blocked)

A(forwarding)-C(forwarding)

C(forwarding)-B(forwarding)

I would like to know if the state of A is correct. Thanks.

2 REPLIES
Anonymous
N/A

Re: switch: spanning tree

sure, there is a normal state. Some port must be blocked to avoid loops and some must be forwarding within Spanning tree.

To have a better understanding of Spanning tree, visit:

http://www.cisco.com/univercd/cc/td/doc/cisintwk/ito_doc/transbdg.htm

New Member

Re: switch: spanning tree

This is the normal operation to prevent network loops. There has to be a root switch according to the algorthm. Since these are all Cisco Switches, the priority is set to 32768 by default. You can adjust the priority if one of the switches is desired to be the root switch.

The switch with the highest bridge priority (the lowest numerical priority value) is elected as the root switch. If all switches are configured with the default priority (32768), the switch with the lowest MAC address in the Layer 2 network becomes the root switch.

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