IPv6 Tutorial
Internet has been growing extremely fast so the IPv4 addresses are quickly approaching complete depletion. Although many organizations already use Network Address Translators (NATs) to map multiple private address spaces to a single public IP address but they have to face with other problems from NAT (the use of the same private address, security…). Moreover, many other devices than PC & laptop are requiring an IP address to go to the Internet. To solve these problems in long-term, a new version of the IP protocol – version 6 (IPv6) was created and developed.
IPv6 was created by the Internet Engineering Task Force (IETF), a standards body, as a replacement to IPv4 in 1998. So what happened with IPv5? IP Version 5 was defined for experimental reasons and never was deployed.
While IPv4 uses 32 bits to address the IP (provides approximately 232 = 4,294,967,296 unique addresses – but in fact about 3.7 billion addresses are assignable because the IPv4 addressing system separates the addresses into classes and reserves addresses for multicasting, testing, and other specific uses), IPv6 uses up to 128 bits which provides 2128 addresses or approximately 3.4 * 1038 addresses. Well, maybe we should say it is extremely extremely extremely huge :)
IPv6 Address Types
| Address Type | Description |
| Unicast | One to One (Global, Link local, Site local) + An address destined for a single interface. |
| Multicast | One to Many + An address for a set of interfaces + Delivered to a group of interfaces identified by that address. + Replaces IPv4 “broadcast” |
| Anycast | One to Nearest (Allocated from Unicast) + Delivered to the closest interface as determined by the IGP |
A single interface may be assigned multiple IPv6 addresses of any type (unicast, anycast, multicast)
IPv6 address format
Format:
x:x:x:x:x:x:x:x – where x is a 16 bits hexadecimal field and x represents four hexadecimal digits.
An example of IPv6:
2001:0000:5723:0000:0000:D14E:DBCA:0764
There are:
+ 8 groups of 4 hexadecimal digits.
+ Each group represents 16 bits (4 hexa digits * 4 bit)
+ Separator is “:”
+ Hex digits are not case sensitive, so “DBCA” is same as “dbca” or “DBca”…
IPv6 (128-bit) address contains two parts:
+ The first 64-bits is known as the prefix. The prefix includes the network and subnet address. Because addresses are allocated based on physical location, the prefix also includes global routing information. The 64-bit prefix is often referred to as the global routing prefix.
+ The last 64-bits is the interface ID. This is the unique address assigned to an interface.
Note: Addresses are assigned to interfaces (network connections), not to the host. Each interface can have more than one IPv6 address.
Rules for abbreviating IPv6 Addresses:
+ Leading zeros in a field are optional
2001:0DA8:E800:0000:0260:3EFF:FE47:0001 can be written as
2001:DA8:E800:0:260:3EFF:FE47:1
+ Successive fields of 0 are represented as ::, but only once in an address:
2001:0DA8:E800:0000:0000:0000:0000:0001 -> 2001:DA8:E800::1
Other examples:
– FF02:0:0:0:0:0:0:1 => FF02::1
– 3FFE:0501:0008:0000:0260:97FF:FE40:EFAB = 3FFE:501:8:0:260:97FF:FE40:EFAB = 3FFE:501:8::260:97FF:FE40:EFAB
– 0:0:0:0:0:0:0:1 => ::1
– 0:0:0:0:0:0:0:0 => ::
IPv6 Addressing In Use
IPv6 uses the “/” notation to denote how many bits in the IPv6 address represent the subnet.
The full syntax of IPv6 is
| ipv6-address/prefix-length |
where
+ ipv6-address is the 128-bit IPv6 address
+ /prefix-length is a decimal value representing how many of the left most contiguous bits of the address comprise the prefix.
Let’s analyze an example:
2001:C:7:ABCD::1/64 is really
2001:000C:0007:ABCD:0000:0000:0000:0001/64
+ The first 64-bits 2001:000C:0007:ABCD is the address prefix
+ The last 64-bits 0000:0000:0000:0001 is the interface ID
+ /64 is the prefix length (/64 is well-known and also the prefix length in most cases)
In the next part, we will understand more about each prefix of an IPv6 address.
@9tut Thank you so much for this Tutorial, This was the most difficult chapter for me now I know I’m gonna make it.
Very Nice Tutorial …
9tut, thanks so much. Its very helpful. :)
This is very helpful tutorial for me.
i want to knw more about addressing and vlms
Thanks. This is very helpful to me for IPv6 key points.
Thank you and everybody else who contributes to this site, without these resources I would have failed my exams, even with the year and a half of schooling in cisco. Your contribution to my studies have been immeasurable, for that I Thank You!
Thanks a lot man, a well done and nice summary of what IPv6 is…
thanks very much , keep it up . it would be great evolution of explanation
great task
How do you subnett IPv6?
@9tut….Thanks a lot.
IPv6 is new to us.As a beginner, it is difficult to study.
Ur explanation is easy to understand and make us clear.
thank you 9tut.com
Thank you 9tut.com Am very grateful. Am sure this will help me pass the exam.
Great summary, thanks 9tut.com
Excellent!!!!Helped me to clarity.Cheers!!!
we don’t want to go for subnetting in ipv6…….ter r 3.4*10^32 ip add r available in ipv6 ………
+ Hex digits are not case sensitive, so “DBCA” is same as “dbca” or “DBca”…
From ipv6 WIKI:
The hexadecimal digits are case-insensitive
Can you verify which once is accurate ?
@pete
not case sensitive = case-insensitive. true
problem solved
Hi, in the Special IPv6 Addresses table lack this value:
Site-local address – FEC0::/10
In this way the table is full and correct…
@ 9tut
thnks to you first for this explanations
explain for me please
:
global unicast address
how it starts (2 and 3) what about the /3 prefix also meant.
+ starts with a 2000::/3 prefix (this means any address beginning with 2 or 3).
@abdou
2000 >>> it is a hexadecimal number means 4 bits binary for every number
2 >>> 0010
/3 >>> means first 3 bits of this (001) that can begin with 2 or 3
hope this may be useful to u ;)
@9tut plz ensure this answer & this tutorial was very useful thanks to u ;)
anyone plz explain
what is “169.254.x.x” in IPv4…is it valid for host ?
@z
windows xp and later will give a random IP on the 169.254.0.0/16 network to hosts that could not get an IP from the DHCP server.
it is the way windows made it so that hosts can still communicate with devices on the network even tho the host did not get a valid configuration from the DHCP server.
Hello,
@9tut : I think you should add fc00::/7 = Unique Local Addresses which can be used like RFC1918 IPv4 private addresses.
Who ever you are… U are Great.. Please dont get tired… you help, encourage people like me..
Happy Holiday.
169 addressing is known as APIPA…
Definition: A feature of Microsoft Windows, APIPA is a DHCP failover mechanism for local networks. With APIPA, DHCP clients can obtain IP addresses when DHCP servers are non-functional. APIPA exists in all modern versions of Windows except Windows NT.
Just Google APIPA and you will find plenty of information on this.
H.
Here is a VCE for IPv6 questions…
http://www.nettechonline.net/techsupp/CCNA/IPV6Exam_hmeister.vce
Enjoy…
thanks hmeister! :)
thk hmeister.keep going
very simple and excellent explanation of IPv6 , never forgettable , thanks
very helpful……….thanks!!!!!!!!!!
GREAT JOB 9TUT
THANKS!!!!!!!!!!!!!!
Excellent….!!!
@9tut: @Xallax: Please validate that Every IPV6 has at least one loopback address. In tutotrial I am not find anything regarding this.
Is it true?? Please explain the same
@arpit
::1/128 is the loopback address by default.
check the second page of this tutorial plz
http://www.9tut.com/ipv6-tutorial/2
Hi,
great site
A small mistake though, if I’m not mistaken myself … you wrote :
“The size of address range assigned to the RIR may vary but with a minimum prefix of /12 and belong to the following range: 2000::/12 to 200F:FFFF:FFFF:FFFF::/64.”
I believe the range is up to 2FFF:FFFF:FFFF:FFFF:FFFF/64 and not 200F
Thanks
Thank you it’s the first time that i read a very helpful tutoriel about ipv6
gr8 information… THANK YOU !!!
“Thank you it’s the first time that i read a very helpful tutoriel about ipv6″
> Agreed.
I passed yesterday. I had a question where I had to identify FF02::9 as a RIP multicast from a list of 4…
FF02::1
FF02::2
FF02::9
another that was clearly not the answer
Great Explanation…
Good For you 9tut.com
Excellent tutorial!
…this site very helpful to everyone, including me preparing for the exam! its my first time to
read IPV6 and its amazing you simplify it for everyone to understand it. Hope you continue
to share your knowledge and also others who visited this site..GBU
Thanks you.It is a very nice tutorial.
may I ask how to configure IPV6 isnt it the same with IPV4 configuration..?
this detail is not enough its jst only base in two or three lines please give more detail on site fr student help
Thanks 9tut
Very nice explanation…easy for be gainer