The use of the symbol '::' MUST be used to its maximum capability.įor example, 2001:db8:0:0:0:0:2:1 must be shortened to 2001:db8::2:1.

RFC 5952 recommends to use the compressed format for IPv6 address textual representation:įor example, 2001:0db8::0001 is not acceptable and must be represented as 2001:db8::1 In its full notation, an IPv6 address is represented in eight groups of four hexadecimal digits (eight 16-bit blocks) separated by colons (:), for example IPv6 addresses are 128-bit identifiers for interfaces and sets of interfaces ( RFC 4291). For Ethernet networks, the Ethernet MAC address (48 bits) may be used for the Interface Identifier, by inserting 16 additional bits, forming what is referred to as an EUI-64 address.IPv6 address examples for different IPv6 address representations and types Finally, the Interface ID is a unique identifier for a particular interface. The Subnet ID is similar to the netmask in IPv4 but is not part of the IP address in IPv6. The Global Routing Prefix is the network ID or prefix of the address for routing.

Multicast: one-to-many – Assigned to a group of interfaces and is typically delivered across multiple hosts.Īn IPv6 Unicast address is composed of the Global Routing Prefix, Subnet ID, and the Interface Identifier.

Anycast: one-to-nearest – Assigned to a group of interfaces, with packets being delivered only to a single (nearest) interface.Unicast: one-to-one – Single Address to Single Interface.The double-colon can only be used once in an address. The address may be further reduced by removing consecutive fields of zeros and replacing with a double- colon. Each segment is a 4-character hexadecimal number, ranging from 0000 to FFFF, representing 16 bits each, totaling to the 128 bits.įor display purposes, an IPv6 address may be presented without leading zeros. IPv6 addresses are 128 bits and consisting of a series of eight segments, separated by a colon. IPv4 addresses are composed of four numerical octets, ranging from 0 to 255, separated by periods, forming a 32-bit address. At first glance, it is evident an IPv6 address, looks nothing like an IPv4 address.

IPv6’s address structure is defined by the IETF as part of RFC 3513 and provides many of the previously discussed advantages over IPv4.

Ipv6 address types