STP managed and unmanged Switches

[nilush]

Hi,

I am planning to implement STP in our network. I created a testing environment including 2 HPE 1920 and two unmanaged switches. STP is configured and working well. So if I connect additional cables between the two 1920s the root bridge keeps all its ports in forwarding stage and the second 1920 switches the ones unnecessary into a discarded state - that's how it should be. Unfortunately there are plenty of unmanaged switches under the desks, do they operate in an STP environment?

I thought in scenario 1 one of the 1920 would switch to a discarded state on one of the ports, where an unmanaged switch is connected to and in scenario 2 both 1920 would disable the ports with the unmanaged switches since there is a loop happening. I have tested my theory and no ports are disabled. Do I need to swap all unmanaged switches to managed one in order to achieve my goal?

Kind Regards

[TerjeAFK]

Unmanaged switches do not participate in STP, ie. they do not send out BPDU. So if you are worried about loops involving those switches you should look at solutions like loop-protect (don't know if the 1920 supports this) or replacing all those unmanaged switches.

[toniino38]

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@TerjeAFK wrote:

Unmanaged switches do not participate in STP, ie. they do not send out BPDU. So if you are worried about loops involving those switches you should look at solutions like loop-protect (don't know if the 1920 supports this) or replacing all those unmanaged switches.

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That's right for unmanaged switches.

You should have only 1920 and configure the MSTP tab :

[Dunky]

Another option is to only allow one MAC address at any one time on the 1920 port...

port-security max-mac-count 1

Steve