The increase in IPv4 address space allocated to Burundi is sign of greater internet use

For IPv4, the domain is < tt > in-addr. arpa </ tt >.

The IP address is represented as a name in reverse-ordered octet representation for IPv4, and reverse-ordered nibble representation for IPv6.

For example, assume the IPv4 address < tt > 208. 80. 152. 2 </ tt > is assigned to Wikimedia.

DHCP is used for IPv4 and IPv6.

The designers of the Internet Protocol defined an IP address as a 32-bit number and this system, known as Internet Protocol Version 4 ( IPv4 ), is still in use today.

ICMP for Internet Protocol version 4 ( IPv4 ) is also known as ICMPv4.

Internet Protocol version 4 ( IPv4 ) is the fourth revision in the development of the Internet Protocol ( IP ) and the first version of the protocol to be widely deployed.

IPv4 is still the most widely deployed Internet Layer protocol.

IPv4 is a connectionless protocol for use on packet-switched Link Layer networks ( e. g., Ethernet ).

IPv6 is intended to replace the older IPv4, which is still employed for the vast majority of Internet traffic as of 2012.

IPv6 implements a new IP address system that allows for far more addresses to be assigned than is possible with IPv4, but as a result the two protocols are not compatible, complicating the transition to IPv6.

With the ever-increasing number of new devices being connected to the Internet, there is a need for more addresses than IPv4 can accommodate.

IPv6, like the most commonly used IPv4 ( as of 2012 ), is an Internet-layer protocol for packet-switched internetworking and provides end-to-end datagram transmission across multiple IP networks.

It is widely expected that the Internet will use IPv4 alongside IPv6 for the foreseeable future.

However, in most respects, IPv6 is a conservative extension of IPv4.

The main advantage of IPv6 over IPv4 is its larger address space.

The length of an IPv6 address is 128 bits, compared to 32 bits in IPv4.

In addition, the IPv4 address space is poorly allocated, with approximately 14 % of all available addresses utilized.

The standard size of a subnet in IPv6 is 2 < sup > 64 </ sup > addresses, the square of the size of the entire IPv4 address space.

Renumbering an existing network for a new connectivity provider with different routing prefixes is a major effort with IPv4.

In IPv4 this is an optional although commonly implemented feature.

In IPv6, the same result can be achieved by sending a packet to the link-local all nodes multicast group at address, which is analogous to IPv4 multicast to address.

IPv4 is described in RFC 791 ( 1981 ).

For link-local addressing IPv4 uses the special block < tt > 169. 254. 0. 0 / 16 </ tt > as described in RFC 3927 while IPv6 hosts use the prefix < tt > fe80 ::/ 10 </ tt >.

Mobile IP for IPv4 is described in IETF RFC 5944, and extensions are defined in IETF RFC 4721.

IPv6 was developed by the Internet Engineering Task Force ( IETF ) to deal with the long-anticipated problem of IPv4 running out of addresses.

The main QoS-related IETF Request For Comments ( RFC ) s are Definition of the Differentiated Services Field ( DS Field ) in the IPv4 and IPv6 Headers ( RFC 2474 ), and Resource ReSerVation Protocol ( RSVP ) ( RFC 2205 ); both these are discussed above.

In addition to IETF RFCs governing UDP, TCP, and IPv4 / IPv6, all seven layers of the OSI communications architecture are addressed.

As of November 2011, the IETF recommends that bogon filters for previously unused IPv4 < tt >/ 8 </ tt > netblocks should be removed, as all have been assigned.

A later IETF document, Special-Use IPv4 Addresses ( RFC 3330 ) describes the usage of the IPv4 address block < tt > 127. 0. 0. 0 / 8 </ tt > for loopback purposes.

The Internet Engineering Task Force ( IETF ) has directed the Internet Assigned Numbers Authority ( IANA ) to reserve the following IPv4 address ranges for private networks, as published in RFC 1918:

ISC is the developer of several key Internet technologies that enable the global Internet ; such as BIND, ISC DHCP, OpenReg, ISC AFTR, an implementation of an IPv4 / IPv6 transition protocol based on Dual-Stack Lite, which is under development by several large ISPs within the IETF protocol standards development process.

The 6bone was a testbed for Internet Protocol version 6 ; it was an outgrowth of the IETF IPng project that created the IPv6 protocols intended to eventually replace the current Internet network layer protocols known as IPv4.

Many worked to clarify the protocol as it gained popularity, and in 1997 RFC 2131 was released, and remains the standard for IPv4 networks.

Version numbers 6 through 9 were proposed for various protocol models designed to replace IPv4: SIPP ( Simple Internet Protocol Plus, known now as IPv6 ), TP / IX ( RFC 1475 ), PIP ( RFC 1621 ) and TUBA ( TCP and UDP with Bigger Addresses, RFC 1347 ).

In computer networking, use of NAT ( Network Address Translation ) ( RFC 1918 ) or PAT ( Port Address Translation ) to cope with the shortage of IPv4 addresses is an example of a kludge.

To alleviate the shortcomings, the Internet Engineering Task Force published in 1993 a new set of standards, RFC 1518 and RFC 1519, to define a new concept of allocation of IP address blocks and new methods of routing IPv4 packets.

RFC 4360 exemplarly defines the " Two-Octet AS Specific Extended Community ", the " IPv4 Address Specific Extended Community ", the " Opaque Extended Community ", the " Route Target Community " and the " Route Origin Community ".

It is defined as OSPF Version 2 in RFC 2328 ( 1998 ) for IPv4.

OSPF reserves the multicast addresses < tt > 224. 0. 0. 5 </ tt > for IPv4 or < tt > FF02 :: 5 </ tt > for IPv6 ( all SPF / link state routers, also known as < tt > AllSPFRouters </ tt >) and < tt > 224. 0. 0. 6 </ tt > for IPv4 or < tt > FF02 :: 6 </ tt > for IPv6 ( all Designated Routers, < tt > AllDRouters </ tt >), as specified in RFC 2328 and RFC 5340.

In the method defined by RFC 2547, BGP extensions advertise routes in the IPv4 VPN address family, which are of the form of 12-byte strings, beginning with an 8-byte Route Distinguisher ( RD ) and ending with a 4-byte IPv4 address.

In IPv4 this is the network with the CIDR prefix 127. 0 / 8 ( RFC 3330 ).

* RFC 2474 — Definition of the Differentiated Services Field ( DS Field ) in the IPv4 and IPv6 Headers

* RFC 3089: A SOCKS-based IPv6 / IPv4 Gateway Mechanism

In the IPv4 address space certain address blocks are specially allocated or reserved for special uses such as loopback interfaces, private networks ( RFC 1918 ), and state-less autoconfiguration ( Zeroconf, RFC 3927 ) of interfaces.