Special IPv6 Addresses

Special IPv6 Addresses

In IPv6 there are some normal and standard types so address and some special type addresses. The special types of IP addresses available are as below:


Loopback address: Similar to the 127.0.0.1 type of IP address in the IPv4 addressing. The address unspecified in IPv6 is 0:0:0:0:0:0:0:1 or also represented by just “::1”. These type of addresses are assigned to the loopback interface through with packets can be sent to itself and check the connectivity between internal components on the system. Such traffic is not forwarded further as it is destined for internal connectivity check.

Unspecified Address:  If no address is present it is represented by the unspecified IP address. This is similar to the 0.0.0.0 of an IPv4 address.  These addresses are not assigned to any interface or as destination address but can be used as a source address when the determination of a unique IP is not yet occurred.

Transition Addresses

As we know there are different transition mechanisms that help in communication of IPv4 and IPv6 devices.

a)      IPv4 compatible address: 0:0:0:0:0:0:a:b:c:d or also written as ::a:b:c:d, where ( a.b.c.d is similar to the Public IPv4 address) are used by IPv6 or IPv4 nodes that communicate with IPv6 over an IPv4 infrastructure.

b)     IPv4 mapped address: the address 0:0:0:0:0:FFFF:a.b.c.d  or ::FFFF:a.b.c.d is an IPv6 i.e 128 bit representation for an IPv4 address

c)      6 to 4 address:  Any IP address beginning with 2002::/16 prefix shows that it is a 6 to 4 address compared to a normal IPv6 address. Any 32bit IPv4 address we can create an IPv6 address for use by the host. Example:  192.168.1.1 will have a 6to4 address as 2002:C0:A8:01:01/48. Using prefix of 48 bits and remaining 16 bits for a subnet field and the next 64bit for host addresses. The syntax would look like: 2002:aabb:ccdd:subnetID: interface id, and aabb:ccdd is the representation of the IPv4 address, a.b.c.d

d)     ISATAP address:  A node assigned with this IP address can be used for Intra-Site Automatic Tunneling Address Protocol (ISATAP) of the IPv6 technology for IP transition. It is a 64bit prefix address represented by 0:5EFE:a.b.c.d where a.b.c.d is the Private IPv4 address.

e)      Teredo address: The prefix used by this address is 2001::/32

See the below table for understanding the IPv4 and corresponding IPv6 term or how the IP looks.

IPv4 Address

IPv6 Address
Address Classes IPv6 does not uses Classes
Uses Multicast addresses ( 224.0.0.0/4) Uses Multicast addresses ( FF00::/8)
IPv4 uses 127.0.0.1 as loopback In IPv6 ::1 is the loopback address
0.0.0.0 is considered IP that is unspecified :: is considered unspecified address
We have Broadcast addresses No Broadcast addresses in IPv6
Internet Routable IPs are Public IP address The Routable IPs are Aggregatable global Unicast
As mentioned in RFC 1918, the Private IP addresses are (10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16) In IPv6 Private address are known as Site Local addresses and represented as (FEC0::/48)
Range of 169.254.0.0/16 is considered APIPA In IPv6 is known as Link Local address (FE80::/64)
Dotted Representation Colon Representation
Network Bits are either represented in dotted or in Slash or prefix notation In IPv6 Network bits represented only by Prefix

The Multicast IP addresses used in IPv6 are as below:

FF01::1           ->                    All Nodes Multicast Address in Interface Local Scope

FF01::2          ->                    All Routers Multicast Address in Interface Local Scope

 

FF02::1         ->                    All Nodes Multicast Address in Link-Local Scope

FF02::2        ->                    All Routers Multicast Address in Link-Local Scope

FF02::5        ->                    OSPFv3 Multicast Address (IPv6) for SPF Routers

FF02::6        ->                    OSPFv3 Multicast Address (IPv6) for Designated Routers

FF02::9        ->                    RIPng Routers

FF02::13     ->                     PIM Routers

 

FF05::2       ->                      All Routers Multicast Address in Site-Local Scope

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