Internet Protocol is a set of technical rules that defines how computers communicate over a network. There are currently two versions: IP version 4 (IPv4) and IP version 6 (IPv6). IPv4 was the first version of Internet Protocol to be widely used, and accounts for most of today’s Internet traffic. There are just over 4 billion IPv4 addresses. While that is a lot of IP addresses, it is not enough to last forever. IPv6 is a newer numbering system that provides a much larger address pool than IPv4, amongst other features. It was deployed in 1999 and should meet the world’s IP addressing needs well into the future.
The major difference between IPv4 and IPv6 is the number of IP addresses. ...view middle of the document...
The IPv6 header is a static header of 40 bytes in length, and has only 8 fields. Option information is carried by the extension header, which is placed after the IPv6 header. If there is no option information, there is no need for extension header, and the packet size is thus reduced. The basic length of the IPv4 header comprises a minimum of 20 bytes (without option fields). The maximum total length of the IPv4 header is 60 bytes (with option fields), and it uses 13 fields to identify various control settings.
The IPv6 node has the ability of attaining dynamically its node and network address. This ability is called Auto configuration. There are two types of auto configuration: stateful and stateless auto configuration.
Routing in IPv4 is much the same as in IPv6 but the addresses are 128-bit instead of 32-bit addresses in IPv4.
The Network Address Translation is used in the current IPv4 Internet protocol to expand the number of addresses. In the IPv6 network with its availability of a large number of addresses for all IP devices, there is no need for translating hundreds of Internal IP addresses into a few global IP addresses.
IPv6 provides superior data security, which includes end-to-end support for user authentication, data integrity, and data encryption. Security in IPv4 networks is limited to tunneling between two networks.
Example of a DHCP Server Configuration
First install DHCPv6 RPM on the server:
# yum -y install dhcpv6
After installing the above RPM you turn on global IPv6 initialization and enable forwarding of IPv6 packets:
# vi /etc/sysconfig/network
Then you turn on IPv6 on a particular device and we will also a set an IPv6 address for that device by adding the following lines:
# vi /etc/sysconfig/network-scripts/ifcfg-eth0
Now you specify the interface for DHCPv6 server: