VLANs, or Virtual LANs, are really the first sign of virtualization that came to networking. Before VLANs we ended up having a whole switch as just one broadcast domain. So that meant that we had routers everywhere to split up …
From a very practical perspective, the layer 2 discovery protocols have been invaluable to me as a network engineer. There are a lot of times when you will come into a situation, depending upon what kind of position that you …
Now that we understand how different VLANs on one switch segregate broadcast domains, we need to be able to allow that VLAN to traverse multiple switches, such that VLAN 50 on my current switch can talk to VLAN 50 on …
Traditional Architecture When you look at the exam topics for the CCNA, you’ll notice that this particular topic feels a little out of place. Cisco is asking us to explain the fundamentals of virtualization, specifically as it pertains to virtual …
Electromagnetic Waves In this lesson we’ll go through some of the fundamentals that 802.11 uses for wireless communication, and mostly as it pertains to just RF, or radio frequencies, and how they interact with the environment. As you probably guessed …
Connection Oriented Vs. Connectionless TCP and UDP are protocols that live up at layer 4. Quick recap, down at layer 2, our data link layer is where our MAC addresses live and protocols like ARP. Layer 3 is the network …
The coming of IP version 6 has been imminent for quite a long time now. Ever since people realized that we were going to run out of public IPv4 addresses in a short period of time, then IPv6 has been …
Layer 2 Addressing At layer 2 is where our Ethernet Frame exists, and first up let’s talk about the type of address that we use at layer 2. At layer 2 is our MAC address ,that’s the Media Access Control …
At layer 1, this is at our physical interface and our physical cabling, where we have configuration characteristics like speed and duplex. Things like your cable length also come into play here. As you may recall, with unshielded twisted pair …
In this section we’re going to go over the physical cables that links all of your infrastructure together. Whether it’s over the WAN, or internally at your organization. See, a lot of network engineers spend a lot of time at …