The Cisco Certified Network Associate v1.0 (CCNA 200-301) exam tests a candidate’s knowledge and skills relating to network fundamentals. At the end of this course, you should be confident about the roles a router plays in a network and its main functions.
In the Cisco world, one of the two network component that you will be working on is a ROUTER. If you remember in your house, you have a router box which you connect to the wall and you enter a password for your home wi-fi, that is a form of router but not the type of router that we will be looking at. The router in your house is not designed to handle and forward network traffic to more than one network.
These are examples of the type of routers you see in homes, they are not enterprise routers that you will see in offices, and also has limited capabilities in terms of what you can do with them and what services you can run on them. They help route traffic between your home network and your ISP for onward transmission to and from the internet. A router for SOHO (small office, home office) use will usually be wireless, and will sometimes include a modem to connect to the internet and even if a household is using an external modem, the following features and concepts will still apply;
- A home router will provide wireless access to individual computers and other devices.
- Most home routers have four Ethernet ports for wired access to computers or other devices.
- Some home routers have USB connectivity for attaching a mass storage device for file sharing.
- Home routers support wireless security.
- Virtually every home router will have a basic firewall and other configuration options.
However, as a CCNA student, routers for SOHO (small office, home office) are NOT the type you will be working on; as they are limited in what services you can be run and configured on them. These type of cisco routers here are the kind of routers you will be installing and configuring. Routers process packets, and these packets are units of data and they operate at 3rd Layer or Layer 3 of the OSI Model which is why they are referred to as “Layer 3 devices”. A Router receives a packet and examines the destination IP address to determine what network the packet needs to
get to, and then sends the packet out of the corresponding interface.
The four arrows pointing in the four 4 directions is the Network icon for a router in a networked environment .
Roles / Functions of a Router
This is an example of a small office where you have 2 departments Accounts on the left and and Operations on the right. The router seats in between them to pass traffic from one subnet to the other subnet and vice versa.
Two main functions of a router
- Determine the best path to available networks
- Forward actual production traffic to those networks