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IPv6 stands for Internet Protocol version 6

New version of the Internet Protocol

Known as IPng (IP Next Generation)

A connectionless Network Layer Protocol IPv6 is designed to solve the problems of IPv4

Alleviate IPv4 address exhaustion

Built-in Security feature Many more..

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Large address space Solve IPv4 address exhaustion

Avoid issues of using NAT Deploy more recent technologies

Stateless autoconfiguration

Security

Multicast

Mobile IP

Cure to routing table growth Hierarchical addressing allows route aggregation

Simplified Header Structure Allow hardware acceleration

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128 bits - written as eight 16-bit hex numbers.

5f1b:df00:ce3e:e200:0000:0800:2078:e3e3

High order bits determine the type of address.

5

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Unicast

Loopback

Unspecified

Scoped addresses:- Link-local

- Site-local

Global

Multicast

Anycast

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Identifies self

Localhost

Like 127.0.0.1 in IPv4

0:0:0:0:0:0:0:1 or ::1

To find if your IPv6 stack works:

Ping6 ::1

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Used as a placeholder when no addressavailable

Initial DHCP request

Duplicate Address Detection (DAD)

Like 0.0.0.0 in IPv4

0:0:0:0:0:0:0:0 or ::

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Scoped address (new in IPv6)

Scope = local link (i.e. VLAN, subnet)

Can only be used between nodes of the same link

Cannot be routed

Automatically configured on each interface

Uses the interface identifier (based on MACaddress)

Format: FE80:0:0:0:

Gives every node an IPv6 address to startcommunications

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Scoped address

Scope = site (a network of links)

Can only be used between nodes of the same

site

Cannot be routed outside the site (i.e. theInternet)

Very similar to IPv4 private addresses Not configured by default

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Generic use. Globally reachable.

Allocated by IANA

To Regional Registries

Then to Tier-1 Providers

Called Top-level Aggregator (TLA)

Then to Intermediate Providers

Called Next-level Aggregator (NLA)

Then to sites

Then to subnets

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Multicast = one-to-many

No broadcast in IPv6. Multicast is used instead,mostly on local links

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One-to-nearest: great for discovery functions

Anycast addresses are indistinguishable fromunicast addresses

Allocated from the unicast addresses space Some anycast addresses are reserved for specific

uses

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IPv6 Prefix Description

0000::/8 Reserved by IETF

2000::/3 Global Unicast

FC00::/7 Unique Local Unicast

FE80::/10 Link Local Unicast

FF00::/8 Multicast

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Used to manage the interactions betweendifferent nodes by exchanging messages.

These messages make it possible for hosts to

communicate with each other. Find link-layer address of neighbor

Find neighbouring routers

Actively keep track of neighbor reachability

Send network information from routers to

hosts

Protocol used for host autoconfiguration

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Number of mechanisms exist; applicability depends onthe interworking scenario.

Main mechanisms Dual stack, IPv6-in-IPv4 tunnelling: automatic, configured, 6over4, 6to4

Protocol translators: NAT-PT

application level gateways, Socks

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IPv4 only Coexistence IPv6 only

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Node has both IPv4 and IPv6 stacks and addresses IPv6-aware application asks for both IPv4 and IPv6

addresses of destination DNS resolver returns IPv6, IPv4 or both addresses

to application IPv6/IPv4 applications choose the address and

then can communicate With IPv4 nodes using IPv4

With IPv6 nodes using IPv6

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IPv4 Datagram

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Intra-Site Automatic Tunnel Addressing Protocol

Automatic tunneling mechanism

For transporting IPv6 packets within a site where a

native IPv6 infrastructure is not yet available. ISATAP router advertise the prefix

Hosts configure themselves according to that

E.g. Prefix = 2001:0DB8:1234:5678::/64

Host IPv4 address = 10.173.129.8

IPv6 address: 2001:0DB8:1234:5678:0000:5EFE:0AAD:8108

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