Root interface manually election

[Joanale]

Hello, 

i’m looking for loop prevention by set priority spanning tree on interfaces to connect to switch core but it not working.

i set the following on interface but the root port still on other way when i put “show spanning rstp status”.

interface ethernet X

spanning-tree rstp priority 16

Is there a way to set manually the root interfaces?.

Thanks,

Joan Ale

[Miguel-Angel_RO]

Joan,

Things are not clear enough for me to give an answer. 

Would it be possible to post a show running-config for core and edge switches?

Mig

[Joanale]

Hi Miguel, thanks for answer. I’m using on uplink switches RSTP and core with MSTP but the STP root can’t be switched by that trunks interfaces.

I’ve this configuration in CORE and can’t activate mstp protocol cause cist.

interface GigabitEthernet 1/22
default-vlan-id 10
slpp packet-rx
slpp packet-rx-threshold 100
no spanning-tree mstp  force-port-state enable
 

Is there a way to activate spanning tree and make the uplink interfaces of other switches show the core as root interface?.

Thanks!.

Joan Ale

[Miguel-Angel_RO]

Joan,

The default STP mode is mstp and you are using rstp command. Double check the stp mode.

As loop prevention protocol, SLPP is a better solution. Simple, fast, stable and efficient.

Mig