DEMO: IPv6 Subnetting - Basics

In one of my prior videos we talked about how our networks are going to be pretty much a /64, but often your internet service provider is going to give you a /48 number that you have to work with. That means you have an extra 16 bits for the subnet portion of this, and that gives you 65,536 different networks to work with. When it comes to subnetting, it's actually much simpler than IP version 4. So here we're just going to learn the basic IP version 6 subnetting — there's a more advanced way that we could do this, but let's look first at a very simple way of subnetting.

A Whole Hextet to Work With

If we have a whole hextet to work with, we have 65,536 different networks that we can work with, and we don't need to borrow any of that for the host portion. The host portion is taken care of — that's another 64 bits, so we've got a crazy amount of host addresses for each one of those networks. We've got a huge range to work with, which really allows us to do a lot of manipulation and things to that address to make it make a lot of sense.

A Simple Example

Let's go over a simple example of subnetting. Here we have the first portion of this, the first network part of it. This first part right here, like I say, is probably assigned by your internet service provider or given to you. So the portion that we have to work with, that we can figure out, is this third hextet or fourth hextet that we have right here.

So how do we want to assign this out? As we see here, we have 454 sites for this with 5,800 nodes per site, so there's 5,800 endpoints per each one of these sites. First of all, this is really not important information at all — we can just ignore this part of it. The reason why we can ignore that part of it is because we've got 64 bits for the host, so 5,800 nodes is nothing compared to the millions upon millions upon billions of possible hosts that we can have for these networks.

So we really only need to worry about this 454. Because this is pretty straightforward — we just need 454 sites — we just start naming them off. The first one's going to be all zeros here, so 00000000000000 Z. If we condense this down, this would just be a zero, so colon zero colon. The next one would be colon 1 colon, the next one colon 2 colon. It's hexadecimal, it's counting in hexadecimal, so it's going to go all the way up to F, and then once it hits F, then it's going to go over to one Z, just like we did the hexadecimal counting.

So really, subnetting with this is pretty straightforward. You have this huge range to work with, you just count up sequentially, and you meet the needs of these 454 sites, or however many sites there is.