Internet Engineering Task Force

With admirable foresight, the Internet Engineering Task Force (IETF) initiated as early as in 1994, the design and development of a suite of protocols and standards now known as Internet Protocol Version 6 (IPv6), as a worthy tool to phase out and supplant IPv4 over the coming years. There is an explosion of sorts in the number and range of IP capable devices that are being released in the market and the usage of these by an increasingly tech savvy global population. The new protocol aims to effectively support the ever-expanding Internet usage and functionality, and also address security concerns.

IPv6 uses a128-bit address size compared with the 32-bit system used in IPv4 and will allow for as many as 3.4×1038 possible addresses, enough to cover every inhabitant on planet earth several times over. The 128-bit system also provides for multiple levels of hierarchy and flexibility in hierarchical addressing and routing, a feature that is found wanting on the IPv4-based Internet. IPv4 and IPv6 are the internet protocols applied at the network layer. IPv4 is the most widely used protocol right now and IPv6 is the next generation protocol for internet. IPv4 is the fourth version of Internet protocol which uses 32 bit addressing whereas IPv6 is a next generation internet protocol which uses 128 bits addressing.

IPv4 allows 4,294,967,296 unique addresses whereas IPv6 can hold 340-undecillion (34, 000, 000, 000, 000, 000, 000, 000, 000, 000, 000, 000, 000) unique IP addresses. IPv4 has different class types: A,B,C,D and E. Class A, Class B, and Class C are the three classes of addresses used on IP networks in common practice. Class D addresses are reserved for multicast. Class E addresses are simply reserved, meaning they should not be used on IP networks (used on a limited basis by some research organizations for experimental purposes). IPv4 has different class types: A,B,C,D and E. Class A, Class B, and Class C are the three classes of addresses used on IP networks in common practice. Class D addresses are reserved for multicast.

Class E addresses are simply reserved, meaning they should not be used on IP networks (used on a limited basis by some research organizations for experimental purposes). Unicast addresses: A Unicast address acts as an identifier for a single interface. An IPv6 packet sent to a Unicast address is delivered to the interface identified by that address. Multicast addresses: A Multicast address acts as an identifier for a group / set of interfaces that may belong to the different nodes. An IPv6 packet delivered to a multicast address is delivered to the multiple interfaces. Anycast addresses: Anycast addresses act as identifiers for a set of interfaces that may belong to the different nodes. An IPv6 packet destined for an Anycast address is delivered to one of the interfaces identified by the address. IPv4 address notation: 239.255.255.255, 255.255.255.0 IPv6 addresses are denoted by eight groups of hexadecimal quartets separated by colons in between them.

An example of a valid IPv6 address: 2001:cdba:0000:0000:0000:0000:3257:9652 Instead of storing network configuration information in local files on each system, DHCP (Dynamic Host Configuration Protocol) enables client systems to retrieve network configuration information each time they connect to the network. A DHCP server assigns IP addresses from a pool of addresses to clients as needed. Assigned addresses are typically temporary, but doesn’t need to be. This technique has several advantages over storing network configuration information in local files: A new user can set up an Internet connection without having to deal with IP addresses, netmasks, DNS addresses, and other technical details. An experienced user can set up a connection more quickly.

DHCP facilitates assignment and management of IP addresses and related network information by centralizing the process on a server. A system administrator can configure new systems, including laptops that connect to the network from different locations, to use DHCP; DHCP then assigns IP addresses only when each system connects to the network. The pool of IP addresses is managed as a group on the DHCP server. IP addresses can be used by more than one system, reducing the total number of IP addresses needed. This conservation of addresses is important because the Internet is quickly running out of IPv4 addresses.

Although a particular IP address can be used by only one system at a time, many enduser systems require addresses only occasionally, when they connect to the Internet. By reusing IP addresses, DHCP lengthens the life of the IPv4 protocol. DHCP applies to IPv4 only, as IPv6 forces systems to configure their IP addresses automatically (called autoconfiguration) when they connect to a network (page 373). DHCP is particularly useful for administrators who are responsible for maintaining a large number of systems because individual systems no longer need to store unique configuration information. With DHCP, the administrator can set up a master system and deploy new systems with a copy of the master’s hard disk. In educational establishments and other open access facilities, the hard disk image may be stored on a shared drive, with each workstation automatically restoring itself to pristine condition at the end of each day.

The DHCP clients request an IP address and other network settings from the DHCP server on the network. The DHCP server in turn leases the client an IP address within a given range or leases the client an IP address based on the MAC address of the client’s network interface card (NIC). The information includes its IP address, along with the network’s name server, gateway, and proxy addresses,including the netmask. Nothing has to be configured manually on the local system, except to specify the DHCP server it should get its network configuration from. If an IP address is assigned according to the MAC address of the client’s NIC, the same IP address can be leased to the client every time the client requests one. DHCP makes network administration easier and less prone to error.