Introduction to Internetworking

Welcome to the exciting world of internetworking. This first
blog will really help you understand the basics of internetworking
by focusing on how to connect networks together using
Cisco routers and switches. First, you need to know exactly what an internetwork is, right?
You create an internetwork when you connect two or more LANs or WANs via a router and
configure a logical network addressing scheme with a protocol such as IP.
I’ll be covering these four topics in this blog:

1.Internetworking basics

2.Network segmentation

3.How bridges, switches, and routers are used to physically segment a network

4.How routers are employed to create an internetwork

I’m also going to dissect the Open Systems Interconnection (OSI) model and describe
each part to you in detail because you really need a good grasp of it for the solid foundation
you’ll build your networking knowledge upon. The OSI model has seven hierarchical
layers that were developed to enable different networks to communicate reliably between
disparate systems. Since this book is centering upon all things CCNA, it’s crucial for
you to understand the OSI model as Cisco sees it, so that’s how I’ll be presenting the seven
layers to you.
Since there are a bunch of different types of devices specified at the different layers of the
OSI model, it’s also very important to understand the many types of cables and connectors
used for connecting all those devices to a network. We’ll go over cabling Cisco devices, discussing
how to connect to a router or switch (along with Ethernet LAN technologies) and even
how to connect a router or switch with a console connection.
We’ll finish the chapter by discussing the three-layer hierarchical model that was developed
by Cisco to help you design, implement, and troubleshoot internetworks.
After you finish reading this chapter, you’ll encounter 20 review questions and four written
labs. These are given to you to really lock the information from this blog into your memory.
So don’t skip them!