What is a Cisco Router for Networking?
First of all, a router is used to connect multiple networks. For example, you can use a Router to connect your Networked Computers to the Internet, thus sharing an Internet connection between multiple users.
The Router will act as a distributor, as a result, it will select the best route for the information to be received quickly.
Routers analyze the data to be sent over one network, as a result, pack it differently and send it to another network or through a different type of network.
They connect their business to the outside world, in addition to protecting information from security threats, and can even decide which computers have priority over others.
The operation of a network consists of connecting computers and peripherals through two parts of the equipment, generally: Switches and Routers. These two elements allow devices connected to the network to communicate with each other and with other networks.
A Router is useful for dividing LANs into separate broadcast domains, especially when connecting these LANs over a WAN.
Routers communicate with each other via WAN connections, and connect networks within local systems as well as the Internet backbone.
They operate at layer 3, making decisions based on network addresses.
The main performances
• The two main functions:
- Determination of the best routes for the incoming data packets.
- Switching packets to the interface Switching packets to the correct outgoing interface.
• They are based on the construction of routing tables and the exchange of the network information they contain with other routers.
Configuration sources
Where can a router be configured from?
1. From the console terminal (a computer connected to the Router through a console port) during its installation.
2. Also through a modem using the auxiliary port.
3. From Virtual Terminals 0-4, after their installation on the network.
4. From a TFTP server on the network.
Internal components of a router configuration (2/1)
• RAM: Stores routing tables, the cache, etc. The content, unfortunately, is lost if the device is turned off or restarted, so it is recommended to save the configuration.
• NVRAM: Nonvolatile RAM stores the backup copy of the router startup configuration file router startup configuration.
• Flash: erasable and reprogrammable ROM that retains the image and microcode of the operating system. Allows SW updates.
• ROM: Power-on diagnostics, a bootstrap program, and minimal operating system software. Minimum operating system.
• Interfaces: They serve as network connections, through which packets enter and leave.
Configuration modes
EXEC user mode (Router>) here shows the image what you can do through this mode:
Privileged EXEC mode (Router #)
In short, these devices are essential when establishing communication between various devices.
And generally, they are not like those provided by telephone companies to access the Internet from our homes.