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Spanning-tree question

We have 2 switches connected by ether channel link with access port , no trunk link, is that ok to turn off the spanning-tree, by the way only 2 switches, no more

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6 REPLIES

Spanning-tree question

You don't have a logical loop but I would still not turn off STP. Things could happen like the Etherchannel could break or someone connects another cable between them and without STP you would have a bridging loop. Why do you want to turn it off?

Daniel Dib
CCIE #37149

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Daniel Dib CCIE #37149 Please rate helpful posts.
New Member

Re: Spanning-tree question

Hello Daniel
Thanks for your reply, actually the design is like this , one is core switch, one is layer3 switch but acting as WAN router, I think that's why that vlan used for this WAN device is running with STP, I am confirming with the vendor who designed this network, is there any benefit to turn off the STP with the case like this?
Thanks

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New Member

Re: Spanning-tree question

Sorry , running without STP

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Hall of Fame Super Blue

Spanning-tree question

As Daniel says it is always best to leave STP on as it doesn't cost you anything to run and it protects against a misconfiguaration or a link failing in certain ways.

However if one of the switches is acting as a router then you could use a L3 etherchannel instead using L3 routed ports and this would disable STP on this link.

Jon

New Member

Re: Spanning-tree question

Hi Jon
Thanks for your reply, actually the physical design is bad here, some servers are directed connected to the core switch without layer2 box , by disabling the STP maybe to reduce the unnecessary BPDU traffic, I guess this is purpose?
Thanks

Hall of Fame Super Blue

Spanning-tree question

If the servers are connected to core switch then these port should be set to either -

1) if the NIC is in a single vlan then - "spanning-tree portfast"

or

2) if the NIC is configured as a trunk link then - "spanning-tree portfast trunk"

either way they should not be generating BPDUs.

BPDU's are not unnecessary, they are very important to protect against loops in your network. You can disable STP if you want. All i can say is that i wouldn't do it because BPDUs do not account for a large amount of traffic and i can't see any advantage to turning it off.

Jon

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