Before knowing about routers we first need to know what happens when you try to open a website or play a video.
When you try to do any activity on the internet, data travels in the network and reaches the destination. For the proper functioning of the network, Router is necessary.
The main purpose of the router is to forward data packets between two or more networks. It connects networks like Local Area Network to Wide Area Network (Commonly called as Internet).
IP addresses are just like real addresses that are used by routers to identify the device/network to forward the data packets.
Purposes of a router:
- Determine the best path for a data packet to reach the destination
- Maintain an internal router table
- Helps communication between networks
There are three more devices that resemble routers but not actually routers.
- Hub
- Switch
- Modem
Hub:
Switch:
Modem:
Now let’s look at different routers and their purposes:
Home / End user grade routers
These kinds of routers are mostly used in homes and small office spaces. They are a combination of tools such as routers, switches, wireless access point & firewall combined. They come with a web based GUI for connection via local IP (192.168.1.1) and configuring the router functionalities. Some of the well known router models include - TP-Link, Netgear & Asus.
Enterprise grade routers:
These routers are built for scalability, security and performance. It can handle heavy routing requirements and can support 1000s of users using the router simultaneously.
It will support routing protocols such as OSPF, BGP, VPNs & QoS.
Might not always have GUI for configuration like Home grade routers. Mostly configured via CMD.
Modularity and Redundancy (hot swappable modules)
Core Routers:
Core routers are usually at the critical part of the internet and route most of the traffic of the company or large enterprise.
Mostly used at the ISP and data centers.
Edge routers:
The purpose of the edge routers are usually to connect the internal networks to the external ones. Acts like a firewall and controls all the incoming and outgoing traffic of the network. It can perform NAT, VPN Termination & Firewalling.
Another important set of router divisions are Wireless and Wired Routers.
Wired Routers:
Wired routers use Ethernet ports for physical connection and is more stable and highly used for latency-sensitive tasks.
Wireless Routers:
It includes Wi-Fi radios in the frequency (2.4GHz/5GHz/6GHz). The purpose of these routers is to connect phone and laptops without any cables.
Usually the modern routers have both.
- Wireless standards
- 802.11ac & ax
Virtual Routers (vRouters / Cloud Routers)
These are not physical routers and are software based routers that run as Virtual Machines or containers.
Some of the Virtual routers are Cisco CSR 1000v, VyOS, AWS Transit Gateway & Google cloud router. These routers are mostly used for flexibility, automation & cost efficiency.
Use cases for these routers are:
- Multi cloud networking
- Edge computing
- CI/CD pipelines
Some famous router models are - Cisco 2901, MikroTik hAP, Netgear Nighthawk