gurfin RiveransRafting

Spanning tree is a system developed to prevent loops in layer two networks. Unlike on L3, frames do not have a TTL that decrements with each hop. To further complicate loop prevention on L2, the usage of broadcast frames is used very frequently. Although this is beneficial for the simplicity of the hosts on the L2 network, this does cause some added complication in loop prevention. Why? 🤷🏻‍♂️ As the need for redundancy in networking grew, the desire to run multiple links between switches needed to be addressed.

In the beginning of LANs the Layer 1 media was shared between all devices in said LAN. They all received and transmitted on the same wires, at the same time. This is whats known as half-duplex (only send or received, not both). In this configuration devices would sometimes send traffic at the same time, which causes interference on Layer 1. The resulting interference can be enough to disrupt the communications. The shared “area” in which devices are connected to is known as a “collision domain”.