Switch
A Layer 2 device that forwards frames between devices on a LAN using MAC addresses.
A switch is a Layer 2 device that learns MAC addresses by inspecting incoming frames and populates a MAC address table (also called a CAM table) to make forwarding decisions. Because each port is its own collision domain, switches eliminate the half-duplex contention that plagued hubs, allowing full-duplex operation per port. The key exam distinction is broadcast versus collision domains: a switch breaks up collision domains per port, but all ports on the same VLAN still share one broadcast domain. Configuring VLANs segments that broadcast domain, and Spanning Tree Protocol (STP) prevents the loops that form when redundant switch links exist.
PlayPrepHQ study notes are written and reviewed against primary exam sources. How we create & review content →