Are we going to run out of 32-bit IP addresses on the internet? I mean
there's only so many right? What are we going to do? I want to show you ipv6 explained simply and
effortlessly so that you understand why we developed it and why we needed
it so that we don't run out of IP addresses across the entire planet
The fear or the concern that I just mentioned (which was running out of 32-bit IP addresses)
was not completely unfounded. In fact, with the limited number of IPv4 addresses that could be
created. Something had to be done to prevent that from happening and that potential problem
was noticed really almost immediately after IPv4 32-bit addresses were standardized and
everyone started using them across the board. It was noticed even then that there was going
to be a problem because we're going to run out of these. There's not going to be enough of them to
go around for everyone to use to connect to the internet or the world wide web. The solution was
to indeed create the IPv6 addresses and they are 128-bits long. And with that lengthy number you
can have this many possible combinations. I'm just going to put this on the screen here. I'm
not even sure what they call this number. I'd have to look it up. You can probably look it up online
or google it but that's the number of combinations of numbers that you can have with IPv6 addresses,
and nerdy mathematicians (I saw this somewhere) once figured out this is approximately this many
addresses, this number on the screen here. It's this many addresses per square meter
of the surface of the entire planet so that's to give you an idea. Now a lot of the expansion
of using up those IPv4 addresses was compensated for by using private IP addresses along with NAT
and PAT for internal local area networks with only an external IP address on a router or a router
firewall having to use one of those assigned IP addresses on the actual internet. And if
you'd like to learn more about that i recommend watching this video that I created where I show
you the difference between Private and Public IP addresses. But long term moving to something like
IPv6 is really going to be the overall solution. Today at the time of this video was made you'll
see IPv6 used on parts of the internet already but it's not extensively used on every desktop,
laptop and smart device that we have out here (at least not yet). IPv6 was designed to be able to
slide into place kind of as a replacement for IPv4 if and when it is needed and we know now that it's
going to be a matter of when at some point. Now more and more parts of the internet are beginning
to use it as time goes on and you it may not even be visible to you so I guess you could say it's
conspicuously and eventually replacing IPv4. There are 2 major issues that plagued IPv4 that IPv6
is actually solving for us: One is that shortage of addresses that we just got done talking about,
the second is an increasing complexity of routing information on a lot of newer routers and
layer 3 capable routing devices that are out there. To make IPv6 addresses easier for us
humans to read and to understand so that we can actually deal with them in a much easier way,
they are written in hexadecimal format not decimal format like we use for IPv4 addresses. An IPv6
address is divided into eight 16-bit groups that are separated by a colon. You will often hear
those in I/T refer to these groups as "hextets." Now I'm not sure this is a standardized name that
we're going to be using but it's one that's kind of been adopted. As more people use IPv6 on their
different components and networks and across the board, they started to call these hextets
so each one of these 16-bit groups is a hextet at this point. This is an example of an IPv6
address. It's not case-sensitive and you don't need to put leading zeroes at the beginning of any
of these hextets. For example in this IPv6 address in the 7th hextet the 03e0 could have been written
as just 3e0 like this. Another shortcut you'll see used with IPv6 addresses is when you have
two consecutive hextets with all zeros, you can actually replace those two hextets with
double colons. So applying that to our example IPv6 address here, we would get this. Now keep
in mind that if you do this you can only do it for one of the double hextets with all zeros.
You can't do that if you have 3 or more hextets with all zeros you can only do it for one of those
pairs that are adjacent to each other. There's one kind of exception to that rule and that is on the
loopback address for IPv6. The loopback address for IPv6 is this. In the case of the loopback
address like this with all preceding zeros you can actually write it like this. And everyone should
begin to understand what that means. In this example, the double colon replaces all of the
zeros preceding the one by compressing zeros like this. When using IPv6 addressing the configuration
and readability is much easier for us human beings. Now at this point before we go any further
I would highly recommend you revamp and study up on hexadecimal numbers and how they're used. You
seldom see them used in IPv4 although I have seen some subnetting methods where they use hexadecimal
numbers to help you subnet but you will see them when looking at mac addresses and of course ipv6
addresses. The great news when it comes to ipv6 addresses is that you will seldom be required to
memorize them or to actually know them like you would IPv4 addresses. In most cases you'll have
a DHCP server issue them out to hosts on a network or they'll be manually issued out by an admin or
a tech and and that's that plain and simple. But for the Network+ Exam you may be asked what the
loopback address is as I showed you previously and you may need to remember that IPv6 addresses
are 128-bits long. Now I just wanted to make that little observation and reminder to you. Those are
2 things that you may be asked on a Network+ or even a CCNA Exam about IPv6. So moving on to the
next portion of this, there are actually 3 types of addresses used in IPv6. You will have unicast,
multicast and what they call anycast. So just a basic explanation of those: unicast and multicast
are really the same as they are with IPv4. Unicast is used for one-to-one communication, multicast is
used for one-to-many communication, and then you get to anycast. Anycast addresses are those are
applied to a group of hosts or devices using the same unicast IP address. They will all provide a
service. If a client sends its data to the anycast address its communication is routed to the nearest
server that's part of that anycast address. Also for the Network+ Exam you will need to know there
are different types of unicast addresses: There are global unicast and link-local unicast. So just
a basic description of those... Global Unicast these are the public-facing IPv6 addresses that
are routable over the internet the world wide web. The host has to have a uniquely assigned address
on the internet to allow these to be used much like registering an IPv4 address on the internet
for usage. If you're going to use an IPv6 address it also has to be registered and nobody else can
be using it on the internet-facing side. You can think of these like you do a public IPv4 address.
It's basically the same thing, only it's for IPv6 these public global unicast addresses will always
start with a 2 or a 3 hexadecimal number. And then we get into link-local unicast. This is
much like a private IPv4 address whereby an IPv6 address is assigned to the system and it can only
communicate with other nodes on the same link. Now a link in the IPv6 world is referring to a network
or subnet or local area network or LAN link. Local addresses will always start with fe80. So
you know what to look for both on the exam and in the real world when you see fe80 in
the first hextet you're talking about a link-local unicast IPv6 address. If you were comparing these
to IPv4 it would be like looking at kind of like looking at an APIPA address of 169.254.0
in the IPv4 world (if you see an fe80 hextet at the beginning). Now the major difference with
that is that with IPv4 you never want to see that and nobody ever wants to see that type of
address because it means kind of self-assigned if you're using windows as an operating system
that means it's been self-assigned. Actually with most operating systems it's been self-assigned if
you see a 169 in front of it but with IPv6 the link-local address is the actual address
used to communicate with other nodes on the same network and I'll remind you that for the
Network+ Exam remember the loopback address this one here. Also remember that it can be
shortened to colon colon one. Also remember when a system has no address specified it will have
all zeros with colons in there or they will list that out that all zeros will be listed
out as abbreviated as just a double colon. In the next video we'll look at the different
protocols used in IPv6 but for now make sure to subscribe to my channel if you haven't already
and click the bell to be notified when the next video is posted and i'll see you there...