In this video, we're going to discuss Spanning Tree
Spanning Tree was developed to stop a layer 2 loops occurring in switch environments.
In transparent switching or transparent bridging which is what Ethernet uses
redundant links introduce loops and Spanning Tree is used to stop those loops.
Spanning Tree has been around for many years
and there been multiple developments and enhancements.
So this is one of the challenges that you’re going to face.
There are different implementations and version of Spanning Tree
and you'll need to know some of those differences.
Spanning Tree are very important protocol in traditional networks
and once again its primary purpose is to stop loops in the switch environment
and not necessarily to stop them as quickly as we would like.
Spanning Tree was developed many years ago
originally being developed for bridges rather than switches
and thus at times a very slow to converge.
In other words, it takes a long time for traffic to be re-routed
if there’s a change in the network topology.
Spanning Tree was once again originally developed for bridges
and bridges do their calculations in software rather than in hardware
which is what switches do today.
So in the past, slower convergence was fine
but that’s a major problem in today’s environments, where we run Voice over IP
or other protocols that require very quick convergence.
Thus the original standard Spanning Tree or 802.1D Spanning Tree
has been superseded by newer versions
such as Rapid Spanning Tree and Multiple Spanning Tree.
because Spanning Tree is of great importance for the CCNA certification
as well as for real deployments
I’m going to start off with original version of Spanning Tree
802.1D and then we'll build on those concepts looking at more and more
complex topologies and other versions of Spanning Tree.