Blocking Loop structure, new to mellanox

I have been working for 13 years as VMware Engineer but don’t have adequate knowledge on Network, I am very sorry.

So Here’s I need your expertise. We have this configuration at customer site.

As usual, we can not change existing alcatel switch.

Initial Configuration

  1. 1.Switch A and Switch B connected to BB switch as L2 Switch
  2. 2.Circle (1) or (2) : STP Enabled

Issue : It actually made whole network system down, Loop happened.

We are going to set followings but we can not test at anywhere.

Could this setup work?

•Switch A, B :

•Port : 1/12 :

•STP rstp

•STP guard loop

•STP guard root

I need your excellent network knowledge

thank you in advance.

WonHee Han.

Hi WonHee,

Based on the topology there is no need to configure root guard or loop guard.

Just make sure that one of the Backbone switches is the root switch, and that the spanning tree port cost on the other Backbone switch is lower than the spanning tree port cost on port 12 of the SX1012s.

This will ensure that port 12 on one of the SX1012 switch will be in discarding/blocking state preventing any loop.