Introduction
to
IPv6
Katherine Douglas, Instructor
Herndon Career Center
Local Cisco Networking Academy
Before we start…
Please write down the following Key Terms on a blank piece of notebook paper leaving a
small underline before and after each word. Label your paper IPv6 Pre/Post Concept
Check.
_____
_____
_____
_____
_____
_____
_____
_____
_____
_____
_____
_____
_____
_____
IPv4
IPng
IPv6
Classful address
NAT
Scalability
VLSM
CIDR
Hierarchy
Aggregation
Successive
Unicast
Multicast
Anycast
_____
_____
_____
_____
_____
_____
_____
_____
_____
_____
_____
_____
_____
_____
More key terms…
_____
_____
_____
_____
_____
_____
_____
_____
_____
_____
_____
_____
_____
_____
_____
_____
_____
_____
_____
_____
_____
Scope of address
Type of address
IPv4-Compatible
IPv4-Mapped
IANA
ARIN
RIPE NCC
APNIC
AfriNIC
ISP
Dual-Stack
Tunneling
Translation
Node
Router
Host
Upper layer
Link
Interface
Address
Packet
_____
_____
_____
_____
_____
_____
_____
_____
_____
_____
_____
_____
_____
_____
_____
_____
_____
_____
_____
_____
_____
Pre Check of Knowledge
1.
Rate yourself as to your perceived knowledge
of these key words.
2.
Assess how much you already know about
these terms by placing a (+), a check (√), or a
zero (0) in the space to the left of each word.



Plus (+) = Expert
Check (√) = Heard of it
Zero (0) = Have not heard of it.
We will do a Post Check at the end of today’s lesson.
IPv6 Defined






Internet Protocol version 6
Originally known as IPng, or IP Next Generation
Network Layer protocol for packet switched
networks
Successor of IPv4 which supports about 4.3
billion addresses (232 addresses)
IPv6 increased the number of addresses to (2128
addresses)
Useful for mobility, QoS, and privacy extension
WOW!





128
2
Addresses
340,282,366,920,938,000,000,000,000,000,000,000,000
340*1036
million, billion, trillion, what?....
NO!! It’s 340 undecillion in America
 or
340 sextillion in Europe
Picture This!

430 quintillion addresses per sq. inch of
the Earth’s Surface





Quintillion = American term for 1018
Trillion = European term for 1018
That’s more than a trillion addresses per square centimeter of
surface on the planet
Each person on Earth could be assigned 7
unique addresses for every atom in his or
her body! (assuming 1,027 atoms per human
for roughly 6.5 billion people alive today)
252 for every star in the known universe!
Questions to ponder?





Do we really need this extremely large
address space?
Is this overkill?
How will this effect our routers and our
routing tables?
What about overhead on equipment and
on our bandwidth?
What happened to IPv5? Did we skip a
version?
Examine the Facts

IPv6 longer address length is needed for:
Routing Aggregation
 Autoconfiguration of Addresses





Improved scalability for multicast routing
More efficient forwarding
Greater flexibility to introduce new options
Flow labeling to aide in QoS and special
handling
Benefits





Easier allocation of address blocks
Flexibility of ISPs to subdivide blocks for
customers
Organizations can subdivide blocks for
internal networks
Unique IP addresses facilitate End-To-End
(E2E) connections
Embedded Quality of Service (QoS) to
support services like VoIP & IP Video
Okay, so what happened to
IPv5?




IPv5 was NOT a successor to IPv6
Known as Internet ST (Stream Protocol)
Intended to be a connection oriented
complement to IPv4
Experimental protocol….Not in public use
IPv4 vs IPv6

IPv4
 Fewer total addresses
 Address depletion
 Scalability problems
 Exponential growth of
Internet & number of
routes
 Need private addressing
and Network Address
Translation (NAT)
 Provides IP for ISPs,
companies, governments,
and educational institutions
 Represented in dotted
decimal notation

IPv6









Does not need NAT
More addresses with
additional levels of hierarchy
to support network growth
Increased bandwidth
overhead
Requires DNS
Difficult to memorize
addresses
Provides IP for ALL citizens!
NO BROADCASTS!
Represented in Colon
Hexadecimal notation
Backward compatible with
IPv4
What’s driving the need??


Internet growth
Mobile devices







PDAs
Mobile phones
Tablet PCs
Gaming
Voice/Video
Security Monitoring
Appliances







Medical Imaging
Animal Tags
Media Services
Traffic Control
Planes
Automobiles
Hotspots
IPv6 Header Fields
Version – version 6 (4 bits)
Traffic Class – packet priority (8 bits) where source
provides congestion or non-congestion control
Flow Label – QoS management (20 bits)
Payload Length – when set to zero, the option is “jumbo
payload” or hop-by-hop which carries optional info that
must be examined by every node (16 bits)
Next Header – next encapsulated protocol compatible
with IPv4 protocol field. (8 bits)
Hop Limit – replaces the TTL (time to live) in IPv4 (8 bits)
Source Address and Destination Address – (128 bits
each)
IPv6 Addresses




Unicast – identifies a single interface on a single
node. A unicast packet is delivered to the
identified single interface.
Multicast - identifies a set of interfaces that
belong to different nodes. A multicast packet is
delivered to all identified interfaces.
Anycast – a global unicast address that is
assigned to a set of interfaces that belong to
different nodes. An anycast packet is delivered
to the closest interface.
Broadcast – Not in IPv6!!!
IPv6 Special Addresses




Reserved – reserved by IETF for special uses. First
eight bits are 00000000. IPv4 embedded addresses use
this block.
Private – private addresses are local to a particular site
or company network and are never routed outside that
network. First nine bits are: 111111101
Loopback – used for testing the “loop back” of the
device. 0:0:0:0:0:0:0:1/128 or ::1/128
Unspecified – used in the source field when a host is
seeking to have its IP address configured. All 128 bits
are zeroes noted as 0:0:0:0:0:0:0:0, ::, or 0::0.
IPv6 Addressing Format



Written in Colon Hexadecimal Notation
Typically see the IPv6 Address followed by a slash “/” for
the Prefix Length
Prefix Length is the number of leftmost bits that
represent the prefix, written in slash notation just like
CIDR in IPv4


IPv6 Ex: 2001:c001:c15c::/48
Two colons “::” represent successive leading zeroes

Example:
2001:0:0:0:260:97FF:FE02:6EA5
same as
2001::260:97FF:FE02:6EA5
IPv6 Unicast Addresses


64 bits for Subnet + 64 bits for Interface ID
Prefix + Subnet ID + Interface ID = IPv6 128 bit
Address




Prefix is the Global Routing Prefix (48 bits)
Subnet ID is the subnet identifier within a site (16 bits)
Interface ID is the interface identifier for a particular host or
other device (64 bits)
Represented in 16 bit Hexadecimal Number
From ONE:
To ONE:
SOURCE -----------------------------Unicast Destination
Routing Prefix


Like the Network ID in IPv4
48 bits
1st three bits are fixed at “001” for unicast
 Next 45 bits - Regional Internet Registries
determine how these bits are allocated.

These bits are typically a combination of Level
Identifier fields.
 For example, you could have: Level 1 Identifer
(10 bits) for largest organizations + Level 2
Identifer (12 bits) for lower level organizations +
Level 3 Identifer (23 bits) for Level 2’s customers

Who’s in charge?


IANA – Internet Assigned Numbers Authority is in
charge of all IP address assignment and internet
parameters. (owned and ran by ICANN)
ICANN – Internet Corporation for Assigned Names and
Numbers is a private, non-profit company responsible for
all registration tasks such as IP address assignment,
domain name assignment, and protocol parameters
management. (ICANN has allowed accredited registrars
to register names in many of the top-level domains)
Often referred to as: IANA/ICANN or ICANN/IANA
Back to IPv6 Addresses…
How do they do it?

IANA assigns largest blocks of addresses
to RIRs (Regional Internet Registries)
What’s an RIR?

An RIR is a Regional Internet Registry that
is responsible for managing IP addresses
and Autonomous System numbers for a
particular region.
So who are the RIRs?





APNIC – Asia Pacific Network Information Centre
responsible for Asia/Pacific region
ARIN – American Registry for Internet Numbers
responsible for North America, part of the Carribean
LACNIC – Latin American and Carribean Internet
Addresses Registry responsible for Latin America and
part of the Carribean
RIPE-NCC – Réseaux IP Européens Network
Coordination Center responsible for Europe, Middle
East, and Central Asia
AfriNIC - African Internet Numbers Registry
responsible for continental Africa and the Indian Ocean
IPv6 Multicast Addresses


1st 8 bits are all 1’s i.e., 1111 1111; Translate into Hex: FF
Indicator (8 bits) + Flags (4 bits) + Scope ID (4 bits) + Group ID
(112 bits) = IPv6 128 bit Multicast Address
 Indicator – 1st eight bits set to 1’s signifying a multicast
packet.
 Flags – 1st three are 0’s. The last is either a “0” for a
permanent/well known multicast address or a “1” for a
transient multicast address.
 Scopes – Globally across the Internet or Locally within the
organization
 Group – Defines a particular group within a scope.
From ONE:
SOURCE
To MANY:
----------------------------- Multicast Destinations
----------------------------- Multicast Destinations
----------------------------- Multicast Destinations
Multicast Scopes





Node-Local
(within a
node)
Link-Local
(within a local
network)
Site-Local
(within a local
site)
OrganizationLocal (within
an
organization)
Global (across
the Internet)
Note: As the Scope ID Value Increases, the Scope
expands to cover larger areas.
Well Known Multicast
Addresses


FF01:0:0:0:0:0:1 used to multicast to all
nodes for node-local. (Notice: FF signifies
multicast, scope id of 1 signifies node-local, and
group id of 1 signifies all nodes)
FF02:0:0:0:0:0:1 used to multicast to all
nodes for link-local. (Notice: FF signifies
multicast, scope id of 2 signifies link-local, and
group id of 1 signifies all nodes)
Multicasting to “all nodes” replaces IPv4 Broadcasts.
More well-known Multicast
Addresses



FF01:0:0:0:0:0:2 used to multicast to all
routers for node-local. (Notice: FF signifies
multicast, scope id of 1 signifies node-local, and
group id of 2 signifies all routers)
FF02:0:0:0:0:0:2 used to multicast to all
routers for link-local. (Notice: FF signifies
multicast, scope id of 2 signifies link-local, and
group id of 2 signifies all routers)
FF05:0:0:0:0:0:2 used to multicast to all
routers for node-local. (Notice: FF signifies
multicast, scope id of 5 signifies site-local, and
group id of 2 signifies all routers)
IPv6 Anycast Addresses







Anycast Packets are new to IPv6
Automatically sends packet to the closest member within a group.
Provides flexibility when requesting a service provided by several
different routers.
Designed for devices within the same network.
Addresses assigned from Unicast Addressing space.
Subnet Prefix (# bits) + Interface Identifier (128 - # bits in Subnet
Prefix) = IPv6 128 bit Anycast Address
 Interface Identifier is set to ALL 0’s.
Subnet-Router Anycast Address is required to communicate with
one of multiple routers in a particular subnet.
From ONE:
SOURCE
-----------------------------------------------------------------------------------------
To ONE of Many:
Multicast Destination
Multicast Destination
CLOSEST Multicast Destination
Deploying IPv6




Migration to IPv6 from IPv4 will not occur
all at once…it’s way too complex
IPv4 and IPv6 must coexist
Migration requires careful planning
Overall transition worldwide will take
several years
Migrating from IPv4 to IPv6

Methods that make the migration easier.




Dual-Stack – running both IPv4 and IPv6
simultaneously. Applications talk to both.
Tunneling – wrapping or packaging one type of
packet into another to be sent on dissimilar network
i.e., tunneling ipV6 packets on IPv4 network
Translation – converting IPv4 to IPv6 and vice versa
which can be complex and result in problems.
Required for devices that only support one version.
(temporary solution until more devices make the
move to IPv6)
IPv6/IPv4 Address Embedding – embeds the IPv4
addresses within the IPv6 address structure
Dual-Stack



Devices are IPv6 Aware
Devices speak both IPv6 and IPv4
Dual Stack is the primary approach for
introducing IPv6 into an IPv4 network
Tunneling




Enables interconnection of IP networks.
IPv6 networks can be connected through
an IPv4 WAN link.
IPv6 packets are encapsulated and
decapsulated by border routers for
transmission over the IPv4 WAN link.
Thus, IPv6 packets are tunnelled through
the IPv4 network cloud.
Translation





Required when IPv6 host needs to
communicate with IPv4 host.
Application Level Gateways (ALGs) are
required to translate.
Can be implemented in border routers and
hosts.
Temporary Solution
Complexity and overhead issues
IPv6/IPv4 Address Embedding



Addresses are in the Reserved Block for
IPv6 addresses.
The first 80 bits are zeroes. (Recall that
the reserved block has zeroes in the first 8
bits)
IPv4 addresses are put in special format
IPv6 address so they are recognized as
IPv4 addresses by IPv6 devices.
Types of Embedding
IPv4-Compatible IPv6 Addresses





Used with IPv6 capable devices
All zeroes for middle 16 bits
80 zeroes + 16 zeroes + 32 bit IPv4 Address
Example in Hybrid IPv4-Compatible format: ::68.87.72.130
Example in Standard IPv6 Hexadecimal format:
::4457:4882
IPv4-Mapped IPv6 Addresses






Regular IPv4 addresses that have been mapped into IPv6 addresses
Used with devices that are only IPv4 capable
All ones for middle 16 bits
80 zeroes + 16 ones + 32 bit IPv4 Address
Example in Hybrid IPv4-Compatible Format:
::FFFF:68.87.72.130
Example in Standard IPv6 Hexadecimal format:
::FFFF:4457:4882
IPv6 Post Check


Now, go back to your IPv6 Pre/Post
Concept Check paper with your Key Terms
Rate your understanding of the Key Terms
on the Right Side. Remember:
(+) = Expert
 (√ ) = Heard of it
 (-) = Have not heard of it


Reflection as a group.
Summary





IPv6 or Internet Protocol Version 6 is the successor to
IPv4 or Internet Protocol Version 4. It is needed to
address the need for additional address space with an
ever growing Internet population as well as new internet
devices.
IPv6 addresses are written in Colon Hex notation.
IPv6 addresses are Unicast, Multicast, and Anycast.
Broadcast is not part of IPv6.
IPv6 has four special addresses: Reserved, Private,
Loopback, and Unspecified.
Two colons in an address represent successive leading
zeroes.
Summary #2



IANA assigns blocks of addresses to RIRs.
RIRs manage addresses for a particular
region.
Full IPv6 deployment will take years. IPv4
and IPv6 must coexist in the meantime.
Dual-Stack, Tunneling, Translation, and
IPv6/IPv4 Address Embedding all make
the migration easier.