Loop Prevention Protocols for Layer 2 Networks

AE

The two protocols used by bridges and switches to prevent loops in a layer 2 network are 802.1d and STP (Spanning Tree Protocol).

802.1d is the original version of Spanning Tree Protocol (STP) that provides a loop-free topology in a LAN. STP works by creating a tree-like structure of the network, where one of the switches is elected as the root bridge. The root bridge is responsible for managing the topology and preventing loops by disabling redundant paths. Each switch in the network calculates its own path to the root bridge and selects the shortest path based on the cost associated with each link. STP is a standardized protocol and is supported by most switches.

STP (Spanning Tree Protocol) is an IEEE 802.1D protocol that provides a loop-free topology in a LAN. STP works by creating a tree-like structure of the network, where one of the switches is elected as the root bridge. The root bridge is responsible for managing the topology and preventing loops by disabling redundant paths. Each switch in the network calculates its own path to the root bridge and selects the shortest path based on the cost associated with each link. STP is a standardized protocol and is supported by most switches.

In summary, both 802.1d and STP are used to prevent loops in a layer 2 network. STP is an updated version of 802.1d and is the most commonly used protocol for loop prevention in modern networks. STP works by creating a loop-free topology in a network by electing a root bridge and disabling redundant paths.