Spanning-tree Nexus Best Practices

opnineopnine · ‎11-13-2015

Hi all,

Its necesary configure in the interfaces vlans spanning-tree?

Or in what cases must we configure spanning-tree in the interfaces vlans?

Thanks

niko · ‎11-13-2015

Hi,

In a best case scenario all hosts will use vPC, so STP would not be required, but, as per Cisco best practice, STP should be always enabled in case of misconfiguration, etc.

Quote: "Spanning Tree Protocol must remain enabled for all VLAN (even if all access devices are vPC-attached to vPC domain). Do not disable spanning-tree protocol!"

For more information feel free to check out the full document yourself: http://www.cisco.com/c/dam/en/us/td/docs/switches/datacenter/sw/design/vpc_design/vpc_best_practices_design_guide.pdf

In case you have some kind of a specific design, please update us with some kind of a topology and more detalied information.

HTH.

opnineopnine · ‎11-13-2015

Hello Niko,

I did not disable the spanning tree , i just add in the vpc the spanning tree port type and in global configuration I set the spanning priority to the vlans.

in the interfaces vlans Im using hsrp and this will be the output for the spann of one of this vlans

VLAN0003
Spanning tree enabled protocol rstp
Root ID    Priority    32771
             Address     0023.04ee.be01
             Cost        1
             Port        4295 (port-channel200)
             Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Bridge ID Priority    32771 (priority 32768 sys-id-ext 3)
             Address     0023.04ee.be0a
             Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Interface        Role Sts Cost      Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
Po10             Desg FWD 1         128.4105 (vPC peer-link) Network P2p
Po20             Desg FWD 1         128.4115 (vPC) P2p
Po200            Root FWD 1         128.4295 (vPC) P2p

!

Can you share what will be configuracion of a SVI with spanning tree please?

thanks.

Jon Marshall · ‎11-13-2015

SVIs are L3 so your question doesn't make sense.

If you have set the priority for the vlans then there is nothing to do with the SVIs.

Perhaps you can clarify ?

Jon

opnineopnine · ‎11-13-2015

hello Jon,

Sorry for my errors, let me get this more clear.

In my 7700 i have vlan 3 and interface vlan 3 with Ip address x.x.x.x and hsrp, this if for my 2 7700 nexus.

Like I said I set the priority for each vlan, do I to add any other configuration regarding spanning tree?

thanks.

niko · ‎11-13-2015

STP is good to go, jus tmake sure root switch is the one you want to be.

For L3 you can use "peer-gateway" vPC domain command, that may be useful one day. More information in Best Practice doc.

opnineopnine · ‎11-17-2015

Hi all,

Thanks all for your help, this is my actual configuration in my two devices

spanning-tree vlan 1-100 priority 16384
spanning-tree vlan 1-100 priority 0

My question is will it be a best practices to add on each trunk interface the commando

spanning-tree guard root ??

Will there be any other thing I need to add?

Thanks all!

opnineopnine · ‎11-18-2015

Hi all,

Im still with the spanning tree issue.

I have the 2 nexus with the following output.

7k2

VLAN0003
Spanning tree enabled protocol rstp
Root ID    Priority    32771
             Address     0023.04ee.be01
             This bridge is the root
             Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Bridge ID Priority    32771 (priority 32768 sys-id-ext 3)
             Address     0023.04ee.be01
             Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Interface        Role Sts Cost      Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
Po10             Root FWD 1         128.4105 (vPC peer-link) Network P2p
Po20             Desg FWD 1         128.4115 (vPC) P2p

7K1

VLAN0003
Spanning tree enabled protocol rstp
Root ID    Priority    32771
             Address     0023.04ee.be01
             This bridge is the root
             Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Bridge ID Priority    32771 (priority 32768 sys-id-ext 3)
             Address     0023.04ee.be01
             Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Interface        Role Sts Cost      Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
Po10             Desg FWD 1         128.4105 (vPC peer-link) Network P2p
Po20             Desg FWD 1         128.4115 (vPC) P2p
Po100            Desg FWD 1         128.4195 (vPC) Edge P2p

will this be ok ?

Ganesh Hariharan · ‎11-13-2015

Hi all,Its necesary configure in the interfaces vlans  spanning-tree?Or in what cases must we configure spanning-tree in the interfaces vlans?Thanks200

Hello,

STP is always recommded to be part of switchig network design. With nexus switch having vPC or Fabric path implementation you shoudl have look on the below link for best recommeded practice.

STP Best practice Nexus

Hope it Helps..

-GI

Rate if it Helps

opnineopnine · ‎11-13-2015

Hello Ganesh,

I was checking the doc, the only thing I not do is "spanning-tree mode rapid-pvst" in none of the 7700 , should I need to apply this command? and if I have, will I have any type of issue in the network?

thanks.

Ganesh Hariharan · ‎11-13-2015

Hello,

Rapid PVST+ is the default mode on Cisco® switches.

You can check by yourself the STP is running by issueing command show spanning-tree vlan 3 for more details.

No additional configiration is required.

Hope it Helps..

-GI

Rate if it Helps