Wednesday, October 12, 2022
Is your network running slow? If so, this might be your problem: Spanning Tree.
The foundation for every network, voice or data, is the proper setup of spanning tree.
Spanning Tree is a protocol that runs on your Cisco switches, and many others. It’s primary use is to resolve loops in your network by creating a logical tree structure between switches.
One switch becomes the root bridge. All other switches calculate the best path to get to the root bridge.
In the event of multiple paths to the root, spanning tree calculates the best path and puts all the other ports into a blocking state.
The switch with the lowest bridge priority becomes the root. If there’s a tie, the switch with the lowest mac address will become the root bridge.
By default, each switch has the same bridge priority, therefore, if you don’t manually change one of them to become the root bridge, one will be selected for you, but not necessarily the best choice. The newly selected root bridge could be a switch that is daisy chained off of several other switches, with a slow uplink speed, and limited backplane processing.
In addition to network speed being impaired, this can cause instability in your network. If one of your switches fails or is taken offline, spanning-tree will adjust instantly, however, if the root bridge is taken down or the path to the root bridge is lost, a new bridge will need to be selected, resulting in a topology change, in which case, the entire network will freeze during this process as no traffic can be forwarded.
The best practice is to make your core switch and/or the switch closest to your servers the root bridge by manually assigning a lower bridge priority.
If you would like our team to help you with configuring Spanning Tree or for more information on Cisco Webex Calling, fill out our form below to connect with our team.
CEO Of Bullfrog Group