If redundant (failover) connections are used (multiple physical connections between an EVO’s virtual switch and a physical switch), Spanning Tree Protocol (STP) must be enabled and configured on both the EVO and the physical switch(es).
This is to prevent loopback errors on the network, which would severely impact communication.
STP needs to be enabled any time there is more than one path to the same device on the network.
Note that the Spanning Tree Protocol adds latency to transmissions, so simply ensuring
there are no network loops is typically preferred over enabling this feature in most
environments.
STP should only be enabled if there’s a specific plan in place for handling loopbacks. Settings to consider for Spanning Tree Protocol:
- Switch priority: sets the BPDU (bridge protocol data unit). The switch in the environment with the lowest priority is selected as the root switch.
- Forward delay: sets the time that is spent in the listening and learning states.
- Hello time: sets the time between each BPDU sent on the port.
- Max age: sets the timeout before the switch saves its BPDU configuration.
Check that all switches agree on an STP policy that ensures the network traffic will be correctly managed over multiple paths.