Repeater, Physical Layer or Layer 1

  • Generates a signal in a LAN

Hub, Physical Layer or Layer 1

  • Broadcasts what it receives
  • A LAN device
  • Connects devices in a single MAC
  • Stores a MAC Address table
  • Unlike a hub, a switch can perform unicasting and send data to the exact recipient
  • Connects two LAN segments that run with the same protocols
  • Can regenerate signals because it contains a repeater and MAC Address reading capability

Router, Network Layer or Layer 3

  • Makes forwarding decisions based on IP Addresses
  • Connects two or more different LANs that have two or more different protocols

Multi-Layer Switch, or Layer 3 Switch

  • Can act as a router and a switch
  • A router and a bridge
  • A bridge can connect two different LAN segments that use the same protocols
  • A router can connect two or more different protocols
  • Can act as a Layer 2 bridge or a Layer 3 switch

Modem

  • Modulator and demodulator
  • A modulator carries digital information on an analog carrier signal
  • A demodulator retrieves the transmitted signal, or digital information

Firewall

  • Provides security to the network
  • Filters packets based on IP Addresses, port numbers, application data, and other data