IPv6 address examples

IPv6 address examples for different IPv6 address representations and types

IPv6 addresses are 128-bit identifiers for interfaces and sets of interfaces. 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

2001:0db8:0a0b:12f0:0000:0000:0000:0001

RFC 5952 recommends to use the compressed format for IPv6 address textual representation:

2001:db8:a0b:12f0::1

Leading zeros MUST be suppressed.

The use of the symbol "::" MUST be used to its maximum capability.

The symbol "::" MUST NOT be used to shorten just one 16-bit 0 field.

The characters "a", "b", "c", "d", "e", and "f" in an IPv6 address MUST be represented in lowercase

Examples for other IPv6 address representations

Integer format

The integer ID of 2001:db8:a0b:12f0::1 is 42540766414390830568948465903729639425

Hexadecimal ID

The hexadecimal ID of 2001:db8:a0b:12f0::1 is 0x20010db80a0b12f00000000000000001

Base 85 ID

The base 85 ID of 2001:db8:a0b:12f0::1 is 9r}Vstbyz7$19|O(~JT0 [rfc1924]

Binary ID

The binary ID of 2001:db8:a0b:12f0::1 is 00100000000000010000110110111000000010100000101100010010111100000000000000000000000000000000000000000000000000000000000000000001

You can use tools like a subnet calculator to show more address details.

IPv6 address example
Fig. 1: IPv6 address processed in GestióIPs online subnet calculator

IPv6 address examples for usage with applications

In resource identifiers like URIs and URLs, the colon (:) character is used to separate the IP address form the port number. As the literal representation of IPv6 addresses contains colon characters, this might cause conflicts. Because of this, literal IPv6 addresses are enclosed in square brackets.

IPv6 addresses in URLs

In an URL, the IPv6 address should be enclosed in "[" and "]" brackets [rfc2732]:

http://[2001:db8:a0b:12f0::1]/index.html

IPv6 addresses including a port number

IPv6 addresses including a port number should be enclosed in brackets [rfc5952]:

[2001:db8:a0b:12f0::1]:21

IPv6 addresses with prefix

The prefix is appended to the IPv6 address separated by a slash "/" character (CIDR notation) [rfc4291]:

2001:db8:a0b:12f0::1/64

IPv6 addresses including a zone identifier (zone index)

A zone identifier within a IPv6 address should be specified separated by "%25" ("%25" is the percent-encoded representation of a literal "%" symbol) [rfc6874]:

2001:db8:a0b:12f0::1%25eth0 or

[2001:db8:a0b:12f0::1%25eth0]:21

RFC 6874 suggests that URI parsers (for example in browsers) accept bare "%" signs when possible:

[2001:db8:a0b:12f0::1%eth0]:80

IP6.ARPA addresses

The IP6.ARPA domain is defined to look up a record given an IPv6 address. The intent of this domain is to provide a way of mapping an IPv6 address to a host name [rfc3596].

The IP6.ARPA address can be formed by the hexadecimal values of an IPv6 address in full notation in reverse order, separated by a dot "." and terminated by the domain "IP6.ARPA".

For example, the IP6.ARPA address of 2001:0db8:0a0b:12f0:0000:0000:0000:0001 would be

1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.f.2.1.b.0.a.0.8.b.d.0.1.0.0.2.IP6.ARPA

Windows UNC (Uniform Naming Convention) path name notation

UNC path names (\\server_ip\share) do not support the colon character. Because of this, Microsoft has created a transcription algorithm to represent an IPv6 address in UNC path names. Addresses in this notation are directly resolved by Microsoft software without DNS queries. To transcribe an address to this format, replace all colons with dashes (-) and append the second-level domain "ipv6-literal.net" separated by a dot to the address.

2001-db8-a0b-12f0--1.ipv6-literal.net

The "%" sign to specify a zone index is replaced by an "s" character:

2001-db8-a0b-12f0--1s4.ipv6-literal.net

IPv6 address types with IPv6 address examples

RFC 3513 defines three types of IPv6 addresses:

Unicast

An identifier for a single interface. A packet sent to a unicast address is delivered to the interface identified by that address.

An example for an IPv6 unicast address is 3731:54:65fe:2::a7

Anycast

An identifier for a set of interfaces (typically belonging to different nodes). A packet sent to an anycast address is delivered to one of the interfaces identified by that address (the "nearest" one, according to the routing protocols' measure of distance). Anycast addresses are allocated from the Unicast address space and are not syntactically distinguishable from unicast addresses.

An example for an IPv6 Anycast address is 3731:54:65fe:2::a8

Multicast

An identifier for a set of interfaces (typically belonging to different nodes). A packet sent to a multicast address is delivered to all interfaces identified by that address.

An example for an IPv6 Multicast address is FF01:0:0:0:0:0:0:1

IPv6 address scopes with IPv6 address examples

Every IPv6 address other than the unspecified address (::) has a specific scope [rfc4007].

IPv6 Global Unicast Address Scope

The IPv6 Unicast space encompasses the entire IPv6 address scope. Exceptions are the multicast range ff00::/8 and those ranges, which have been allocated for other purposes (see table "IPv6 Special-Purpose Addresses").

The block 2000::/3 represents the assignable Global Unicast address scope [IANA].

Name	Example	Description	RFCs
Global Unicast 2000::/3	3731:54:65fe:2::a7	Aggregatable global unicast address format for use in the Internet	[rfc4291][rfc3587]

IPv6 Special-Purpose Addresses [IANA]

Name	Example	Description	RFCs
unspecified ::/128	::/128	The unspecified address indicates the absence of an address. One example of its use is in the Source Address field of any IPv6 packets sent by an initializing host before it has learned its own address. It must never be assigned to any node.	[rfc4291]
loopback ::1/128	::1/128	The unicast address 0:0:0:0:0:0:0:1 is called the loopback address. It may be used by a node to send an IPv6 packet to itself. It must not be assigned to any physical interface. It is treated as having Link-Local scope, and may be thought of as the Link-Local unicast address of a virtual interface (typically called the "loopback interface") to an imaginary link that goes nowhere	[rfc4291]
IPv4-mapped Address ::ffff:a.b.c.d/96	::ffff:10.0.0.3/96	IPv6 transition mechanism. IPv6 address which contains an embedded 32-bit IPv4 address. IPv4-mapped addresses are used to represent IPv4 addresses using the IPv6 API (e.g., on AF_INET6 sockets). IPv4 packets going to IPv6 applications on a dual-stack node reach their destination because their addresses are mapped by using IPv4-mapped IPv6 addresses.	[rfc4038][rfc2765][rfc4942]
IPv4-translated Address ::ffff:0:a.b.c.d/96	::ffff:0:10.0.0.3/96	IPv6 transition mechanism. Used by the Stateless IP/ICMP Translation (SIIT) protocol	[rfc6052][rfc2765]
Discard-Only Address Block 100::/64	100::/64	Block with the purposes of implementing an IPv6 Remote Triggered Black Hole (RTBH) configuration.	[rfc6666]
IETF Protocol Assignments 2001::/23		Initial assignments of IPv6 Sub-Top-Level Aggregation Identifiers (Sub-TLA ID) to the Address Registries. It is intended as technical input to the Internet Assigned Numbers Authority as an input to the process of developing guidelines for the allocation of IPv6 addresses.	[rfc2928]
Teredo 2001:0000::/32	2001:0000:6dcd:8c74:76cc:63bf:ac32:6a1/64	IPv6 tunneling protocol. Teredo tunneling enables nodes located behind one or more IPv4 Network Address Translations (NATs) to obtain IPv6 connectivity by tunneling packets over UDP. Running the service requires the help of "Teredo servers" and "Teredo relays".	[rfc4380]
Benchmarking 2001:0002::/48	2001:0002:cd:65a:753::a1/64	Assigned to the Benchmarking Methodology Working Group (BMWG) for benchmarking IPv6 (corresponding to 198.18.0.0/15 for benchmarking IPv4)	[rfc5108]
Documentation 2001:db8::/32	2001:db8::a3/64	Used for documentation purpose only.	[rfc3849]
Orchid 2001:0010::/28	2001:11::3f4b:1aff:f7b2/28	Overlay Routable Cryptographic Hash Identifiers (ORCHID) is an experimental class of IPv6-address- like identifiers. These identifiers are intended to be used as endpoint identifiers at applications and Application Programming Interfaces (API) and not as identifiers for network location at the IP layer, i.e., locators. They are designed to appear as application layer entities and at the existing IPv6 APIs, but they should not appear in actual IPv6 headers.	[rfc4843]
6to4 2002::/16	2002:6dcd:8c74:6501:fb2:61c:ac98:6be/64	IPv6 tunneling protocol. Connection of IPv6 Domains via IPv4 Clouds. 6to4 uses dedicated relay routers to transport encapsulated IPv6 packets across an IPv4 network. It does not requiere an explicit tunnel setup. IPv6 packets are encapsulated by adding an IPv4 header with the Protocol field set to 41. The mechanism is intended as a start-up transition tool used during the period of co-existence of IPv4 and IPv6. It is not intended as a permanent solution.	[rfc3056]
Unique Local Addresses (ULAs) fc00::/7	fd07:a47c:3742:823e:3b02:76:982b:463/64	IPv6 unicast addresses are globally unique and are intended for local communications, usually inside of a site. These addresses are not expected to be routable on the global Internet.	[rfc4193]
Link-Local Addresses fe80::/10	fea3:c65:43ee:54:e2a:2357:4ac4:732/64	Link-Local addresses are designed to be used for addressing on a single link for purposes such as automatic address configuration, neighbour discovery, or when no routers are present. Routers must not forward any packets with Link-Local source or destination addresses to other links.	[rfc4291]

Other IPv6 addresses

Name	Example	Description	RFCs
IPv4-compatible 0::0:a.b.c.d/96	::10.0.0.3/96	IPv6 address which contains an embedded 32-bit IPv4 address. An IPv6 address, assigned to an IPv6/IPv4 node, which bears the high-order 96-bit prefix 0:0:0:0:0:0, and an IPv4 address in the low-order 32-bits. IPv4-compatible addresses are used by automatic tunneling.	[rfc1933][rfc2765]
IPv4-Embedded IPv6 Address 0064:ff9b:/96	64:ff9b:cd:65a:0000:2:6dcd:8c74/96 64:ff9b:cd:65a:0000:6dcd:8c74:0000/64 64:ff9b:6dcd:6d:0000:cd8c:7400:3/56 64:ff9b:1:6dcd:0000:8c74:0000:0000/48 64:ff9b:006d:cd8c:0000:7400:0000:0000/40 64:ff9b:6dcd:8c74:0000:0000:0000:0000/32	IPv6 address which contains an embedded 32-bit IPv4 address constructed according to the rules defined in [RFC6052]. IPv4-embedded IPv6 addresses are composed of a variable-length prefix, the embedded IPv4 address, and a variable-length suffix.	[rfc6052]
EUI-64 addresses x:x:x:xxFF:FExx:x:x:x	2001:db8:a:a:1234:56ff:fe78:9000	IPv6 address with embedded MAC address. Allows hosts to assign itself a IPv6 address on basis of it's already unique MAC address using Stateless Address Autoconfiguration (SLAAC). This mechanism is one of the key benefits over IPv4 because it's eliminates the need of DHCP or manual configuration.	[rfc4291]
ISATAP x:x:x:x:0000:5efe:x:x/64	fe80:4:6c:8c74:0000:5efe:109.205.140.116/64 (link-local) 24a6:57:c:36cf:0000:5efe:109.205.140.116/64 (global-unicast) 2002:5654:ef3:c:0000:5efe:109.205.140.116/64 (global-unicast (6to4))	IPv6 tunneling protocol. ISATAP (Intra-Site Automatic Tunnel Addressing Protocol) is an IPv6 transition mechanism meant to transmit IPv6 packets between dual-stack nodes on top of an IPv4 network.	[rfc4214]

IPv6 Multicast address examples

IPv6 Multicast addresses fall under the range ff00::/8 ([rfc2375][IANA])

Address	Scope	Description	RFCs
FF01:0:0:0:0:0:0:1	Node-Local Scope.	All Nodes Address	[rfc2375]
FF01:0:0:0:0:0:0:2	Node-Local Scope.	All Routers Address	[rfc2375]
FF01:0:0:0:0:0:0:FB	Node-Local Scope.	mDNSv6	[rfc6762][rfc2375]
FF02:0:0:0:0:0:0:1	Link-Local Scope.	All Nodes Address	[rfc2375]
FF02:0:0:0:0:0:0:2	Link-Local Scope.	All Routers Address	[rfc2375]