In our environment they have 2 sites..Main site and Fail over Site.
A Vendor , incidentally or accidentaly, brought a blade and plugged it into a switch, and created topology change or loop (I am not sure which one), the main site failed over however since the VMware environment was not properly set up for failover since they have affinity rules set up,most of the VMs did not failover..
I would like to know what could have been done on the switch to prevent this catastrophe in the future.
I have asked questions in the past, and some experts said , it is better practice to configure unused switch ports as access ports, I have done some reading and some articles say even if a switch port is in access mode, it will still send or receive BPDUs, which means it can cause topology change or loop.
Any idea ?