Bridges, Routers and Gateways A Bridge is used to connect multiple LAN segments Layer 2 routing(Ethernet) Does not know P address Varying levels of sophistication Simple bridges just forward packets smart bridges start looking like routers A Router is used to route connect between different networks using network layer address Within or between Autonomous Systems Using same protocol( e.g., IP, ATM) a Gateway connects between networks using different protocols Protocol conversion Address resolution These definitions are often mixed and seem to evolve!Eytan Modiano Slide 19 Bridges, Routers and Gateways • A Bridge is used to connect multiple LAN segments – Layer 2 routing (Ethernet) – Does not know IP address – Varying levels of sophistication Simple bridges just forward packets smart bridges start looking like routers • A Router is used to route connect between different networks using network layer address – Within or between Autonomous Systems – Using same protocol (e.g., IP, ATM) • A Gateway connects between networks using different protocols – Protocol conversion – Address resolution • These definitions are often mixed and seem to evolve!