Router

  • A networking device that forwards data packets between computer networks
  • Connected to at least two networks, commonly two LANs, two WANs, or a LAN and its ISP's network
  • ISP means Internet Service Provider
  • A Layer 3, or Network Layer, device
  • Has interfaces that connect to different LANs

Bridge

  • A Repeater with the function of reading MAC Addresses
  • A Layer 2 device
  • Used to interconnect two LANs that use the same protocol
  • A two-port device

Two Types of Bridges

  1. Transparent Bridges
  2. Source Routing Bridges

Transparent Bridge

  • Stations are fully unaware of its existence
  • Reconfiguration of the station is unnecessary when the bridge is added or removed from the network

Source Routing Bridge

  • The source station performs the routing operation
  • The frame specifies which route to follow

Bridge and Router

FeatureBridgeRouter
OSI LayerLayer 2, or Data LinkLayer 3, or Network
AddressingMAC AddressIP Address
ScopeConnects segments of the same networkConnects different networks
IntelligenceSimple, forwards or filters framesComplex, finds the optimal path
BroadcastsForwards broadcasts to all segmentsUsually blocks broadcasts to save bandwidth