Router

Definition

A Router is a networking device that plays a crucial role in connecting different computer networks.

Context

• Routers are like the traffic controllers of the digital world, ensuring data packets reach their destinations smoothly.
• Two category of routers are:

1. Network routers that function between distinct networks. They may including specialized security functions.
2. Small office/Home office (SOHO) routers that work stuck under desks and other random places. They typically contain other functions like: Network Address Translation

Function

• Routers **forward data packets** between various computer networks or sub-networks. They serve two primary purposes:
  • Traffic Management**: Routers direct data packets to their intended **IP addresses**, ensuring efficient communication between networks.
  • Shared Internet Access**: They allow multiple devices within a network to use the same **Internet connection**.

Types of Networks

• LAN (Local Area Network)**: A group of connected devices within a specific geographic area. A single router typically serves a LAN.
• WAN (Wide Area Network)**: A large network spread across a vast geographic area. Organizations with multiple locations use LANs that connect to form a WAN. WANs often require multiple routers and switches.

How Routers Work

  - Imagine a router as an **air traffic controller** guiding data packets (like aircraft) to their destinations.
  - Routers maintain an **internal routing table**, listing paths to various network destinations.
  - When a packet arrives, the router reads its header, determines the destination IP address, and consults the routing table to find the most efficient path.
  - It then forwards the packet to the next network on its journey.

Router vs. Modem

  - **Router**: Manages data flow within and between networks. It doesn't directly connect to the Internet.
  - **Modem**: Connects networks to the Internet by converting signals from an ISP into a digital format.
  - Together, they ensure devices can access the Internet and communicate within local networks.

Security

• On line check of routers

References

• What is a router? | Router definition | Cloudflare. https://www.cloudflare.com/learning/network-layer/what-is-a-router/.
• Router (computing) - Wikipedia. https://en.wikipedia.org/wiki/Router_%28computing%29.
• What is a Router? - Definition and Uses - Cisco. https://www.cisco.com/c/en/us/solutions/small-business/resource-center/networking/what-is-a-router.html.
• Router Definition & Meaning - Merriam-Webster
• Cloudflare's explanation
• Cisco's insights