Interconnection Devices
Repeater: PHY device that restores data and collision signals: a digital amplifier
Hub: Multi-port repeater + fault detection
Bridge: Data link layer device connecting two or more collision domains. MAC multicasts are propagated throughout “extended LAN.”
Router: Network layer device. IP, IPX, AppleTalk. Does not propagate MAC multicasts.
Switch: Multi-port bridge with parallel paths
These are functions. Packaging varies.