The two main functions of a router are:
- Packet forwarding: Routers receive data packets from one device and forward them to another device on the same network or a different network. They do this by looking at the destination IP address of the packet and using their routing table to determine the best path to the destination.
- Routing: Routers use a routing table to determine the best path to a destination. The routing table is a database that contains information about all the networks that the router knows about, as well as the cost of reaching each network. Routers use this information to calculate the shortest path to the destination and forward the packet accordingly.
In addition to these two main functions, routers can also perform other tasks such as:
- Network address translation (NAT): NAT allows a router to translate the IP addresses of devices on a local network to a different set of IP addresses when they communicate with the internet. This can be useful for security reasons or to conserve IP addresses.
- Firewall: Some routers include a firewall, which can help protect a network from unauthorized access.
- Quality of service (QoS): QoS allows routers to prioritize certain types of traffic, such as voice or video traffic. This can help to ensure that these types of traffic are not interrupted by other types of traffic.
Routers are essential devices for connecting networks together and routing traffic between them. They play a vital role in the internet and other large networks.