IPv6 Address configurations

Just thought of summarizing some key points about IPv6 ( Internet Protocol Version 6 ).

Key points about IPv6

• It has been designed to replace the age old, reliable IPv4.
• IPv4 has been very good. Has done its job.. It just cant take the current load.
• IPv6 is efficient and more secure.

Let me start with asking you guys a question ?

How do we assign an IPv6 address. Read on :-)

 
Address configuration.

stateful Address Configuaration

• Address configuration with DHCP

Stateless Address Configuration :

• Hosts automatically configure themselves.
• Addresses derived from prefixes advertised by local routers
• The presence of a router is not mandatory

IPv4 had the concept of Unicast Broadcast and Multicast. For unicast and Multicast, the explanation remains the same. There is no broadcast as such in IPv6. A good news.. :-) Less network chaos..

 Address types

 Unicast Addresses

A unicast address identifies a single interface

The following types of addresses are unicast IPv6 addresses:

Global unicast addresses

·         equivalent to public IPv4 addresses.

·         globally routable and reachable on the IPv6 portion of the Internet.

·         The three high-order bits are set to 001. The address prefix for currently assigned global addresses is 2000::/3

Local use Unicast Addresses.

There are two types of local-use unicast addresses:

·         Link-local addresses.

·         Automatically configured.

·         Always begin with FE80

·         Comparable to IPv4 APIPA ( Automatic Private Internet Protocol Addressing )

·         The scope of a link-local address is the local link.

·         Site-local addresses.

·         Equivalent to the IPv4 private address space (10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16).

·         Not routed on internet.

·         A site is an organization network or portion of an organization's network that has a defined geographical location (such as an office, an office complex, or a campus).

·         Not automatically configured. Must be assigned either through stateless or stateful address configuration processes.

·         Always begin with FEC0

 

Unique local IPv6 unicast addresses

·         Designed to replace site-local addresses with an address that is private to an organization, yet unique across all of the sites of the organization.

·         All unique local addresses have the address prefix FC00::/7

·         Unique local addresses have a global scope but their reachability is defined by routing topology.

·         Organizations will not advertise their unique local address prefixes outside of their organizations or create DNS AAAA entries with unique local addresses in the Internet DNS.

 

Special addresses

·         Unspecified address

·         Unspecified address (0:0:0:0:0:0:0:0 or ::) is only used to indicate the absence of an address.

·         Equivalent to the IPv4 unspecified address of 0.0.0.0.

·         The unspecified address is never assigned to an interface or used as a destination address.

·         Loopback address

·         The loopback address (0:0:0:0:0:0:0:1 or ::1) is used to identify a loopback interface, enabling a node to send packets to itself.

·         Equivalent to the IPv4 loopback address of 127.0.0.1.

 

Compatibility Addresses

·         IPv4-compatible address

·         The IPv4-compatible address, 0:0:0:0:0:0:w.x.y.z or ::w.x.y.z (where w.x.y.z is the dotted decimal representation of an IPv4 address), is used by IPv6/IPv4 nodes that are communicating using IPv6.

·         When the IPv4-compatible address is used as an IPv6 destination, the IPv6 traffic is automatically encapsulated with an IPv4 header and sent to the destination using the IPv4 infrastructure.

·         IPv4-mapped address

·         The IPv4-mapped address, 0:0:0:0:0:FFFF:w.x.y.z or ::FFFF:w.x.y.z, is used to represent an IPv4-only node to an IPv6 node.

·          It is used only for internal representation.

·         The IPv4-mapped address is never used as a source or destination address of an IPv6 packet.

·         6to4 address

·         The 6to4 address is used for communicating between two nodes running both IPv4 and IPv6 over an IPv4 routing infrastructure.

·         The 6to4 address is formed by combining the prefix 2002::/16 with the 32 bits of a public IPv4 address, forming a 48-bit prefix.

 

 

Multicast Addresses

·         In IPv6, multicast traffic operates in the same way that it does in IPv4.

·         Always begins with “FF”.

·         Multicast addresses cannot be used as source addresses or as intermediate destinations in a Routing extension header.

Solicited Node Address.

·         Replaces the IPv4 ARP mechanism.

·         The solicited-node address facilitates the efficient querying of network nodes during address resolution.

·         The solicited-node multicast address is comprised of the prefix FF02::1:FF00:0/104 and the last 24-bits of the IPv6 address that is being resolved.

·         By using the solicited-node address, very few nodes are disturbed during address resolution.

 

Anycast Addresses

·         An anycast address is assigned to multiple interfaces.

·         Packets addressed to an anycast address are forwarded by the routing infrastructure to the nearest interface to which the anycast address is assigned.