A router is a network device that connects multiple network segments into an internetwork. Routers are intelligent devices that make routing decisions ie. Determine the best possible path for data packets to travel between sender and receiver. In large networks data may be sent to many routers before it reaches its final destination. Routers use routing tables to determine the next hop and they also keep track of the condition of the network to possibly send a packet on a route with less traffic or interference.
Routers have multiple ports or connection points for connection to different network segments to enable routing. At a minimum, most routers have at least three (3) ports which connects to different devices and have different uses.
The ports include:
- A high-speed serial port (usually labeled Wan 0 or Serial 0). This port usually connects to either a modem bank or WAN connection device. There may be many of these ports on a single router.
- A port that connects the router to the LAN usually labeled LAN 0 or Eth0.
- A serial port that you connect to a terminal or PC running terminal software for router configuration.
