Identify and describe several common problems at Layer 2 of a network

What will be an ideal response?

There are a variety of answers to this, but the following are common issues:
Power failure: Most devices on a network do not have redundant power supplies, so power failure can cause network outages.
Module failure: This can happen when a piece of equipment (or a module within a piece of equipment) fails, causing an interruption in network operation.
Layer 2 loops: These issues can happen when STP is not in place or breaks down, resulting in MAC table corruption or broadcast storms.
Port configuration: This can happen if parameters on one end of a connection do not match parameters on the other end of the connection.