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Community Member

How to disable STP

I have a 2950 - 24 switch

Ever since I installed it on my network, every time that a server is rebooted, the server logs errors about being unable to communicate with other server.

This only happens in the first seconds of the Server's reboot process, after that, it is all good.

I know there is a feature on the switches that perhaps is causing the server's port to be block during the server's reboot process, and this is called STP.

Can anyone confirm that I am on the right track and if this feature is Turned on by default on these 2950 switches and if so, how do I disable it?


Community Member

Re: How to disable STP

if you really want to disable STP you can by typing conf t

no spanning-tree vlan (vlan-id)


you can also type sh spanning-tree vlan to verify yuor entries.

make sure you do not end up with a routing loop and verify cabling on your switches.

the feature is turned on by default as well.

Community Member

Re: How to disable STP

as of right now, I don't have any Vlans setup, so all devices I have connected to the switch belong to my single and only subnet

With this said, to what vlans do my workstations and servers belong to if no vlans have been setup?

is Vlan 1 the default one where all workstations belong to when nothing is setup in a single 2950 switch?

Re: How to disable STP

Configure 'spanning-tree portfast' on the port to which the server is connected. This would the put the port in a forwarding mode right away by skipping the listening and learning states when the port is activated.

Pls. rate the post if it helped.



Community Member

Re: How to disable STP

is this something you can do individually on each port without having to modify STP?


Re: How to disable STP

You can do it individually on each port by entering the 'spanning-tree portfast' command. It will probably be easier to use the global 'spanning-tree portfast default' command; what it does is that it enables portfast on all access ports.

WARNING : Please make sure that you configure portfast on access ports only and ensure that only end-hosts are connecting to these ports. I also recommend that you enable the bpduguard feature on the access ports to minimize the chance of someone plugging another switch to the access ports. Use the 'spanning-tree bpduguard default' global command to ensure that bpduguard is enabled on portfast ports also.

Cisco Employee

Re: How to disable STP

In addition to the above, it's advisable to use the macro command "switchport host" which also disables trunk and etherchannel negotiation.

More on this here:



*Please rate helpful posts.

Community Member

Re: How to disable STP

spanning tree portfast on each interface

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