Thomas McGirt
Unit 9 Assignment: Research Paper
8/17/14
The current version of the Internet Protocol IPv4 was first developed in the 1970s, and the main protocol standard RFC 791 that governs IPv4 functionality was published in 1981. With the unprecedented expansion of Internet usage in recent years, especially by population dense countries like India and China, the impending shortage of address space (availability) was recognized by 1992 as a serious limiting factor to the continued usage of the Internet run on IPv4 (Das, 2013).
The Internet Protocol version 6 (IPv6) is the latest revision of the Internet Protocol (IP). It is a communications protocol that provides an identification and location system for computers on networks and routes traffic across the Internet. IPv6 was developed by the Internet Engineering Task Force (IETF) to deal with the long-anticipated problem of IPv4 address exhaustion. IPv6 is intended to replace IPv4, which still carries the vast majority of Internet traffic as of 2013. As of late November 2012, IPv6 traffic share was reported to be approaching 1% (Wikipedia, 2013).
On the Internet, data is transmitted in the form of network packets. IPv6 specifies a new packet format, designed to minimize packet header processing by routers. Because the headers of IPv4 packets and IPv6 packets are significantly different, the two protocols are not interoperable. However, in most respects, IPv6 is a conservative extension of IPv4. Most transport and application-layer protocols need little or no change to operate over IPv6. Internet Protocol Security (IPsec) was originally developed for IPv6, but found widespread deployment first in IPv4, for which it was re-engineered. IPsec was a mandatory specification of the base IPv6 protocol suite, but has since been made optional (Wikipedia, 2013).
Multicasting is the transmission of a packet to multiple destinations in a single send operation, it is part of the base specification in IPv6. In IPv4 this is an optional although commonly implemented feature. IPv6 multicast addressing shares common features and protocols with IPv4 multicast, but also provides changes and improvements by eliminating the need for certain protocols. IPv6 also provides for new multicast implementations, including embedding rendezvous point addresses in an IPv6 multicast group address, which simplifies the deployment of inter-domain solutions (Network Working Group, 2013).
In IPv6, the packet header and the process of packet forwarding have been simplified. Although IPv6 packet headers are at least twice the size of IPv4 packet headers, packet processing by routers is generally more efficient, thereby extending the end-to-end principle of Internet design. Unlike mobile IPv4, mobile IPv6 avoids triangular routing and is therefore as efficient as native IPv6. IPv6 routers may also allow entire subnets to move to a new router connection point without renumbering (Network Working Group , 2013).
IPv4 limits packets to 65,535 (216-1) octets of payload. An IPv6 node can optionally handle packets over this limit, referred to as jumbograms, which can be as large as 4,294,967,295 (232−1) octets. The use of jumbograms may improve performance over high-MTU links. The use of jumbograms is indicated by the Jumbo Payload Option header (Network Working Group, 2013).
Like IPv4, IPv6 supports globally unique IP addresses by which the network activity of each device can potentially be tracked. The design of IPv6 intended to re-emphasize the end-to-end principle of network design that was originally conceived during the establishment of the early Internet. In this approach each device on the network has a unique address globally reachable directly from any other location on the Internet. In the effort to conserve address space, network address translation (NAT) confuses network address spaces, hosts, and topologies in IPv4 (Wikipedia, 2013).
The 128 bits of an IPv6 address are represented in 8 groups of 16 bits each. Each group is written as 4 hexadecimal digits and the groups are separated by colons (:). The address 2001:0db8:0000:0000:0000:ff00:0042:8329 is an example of this representation. For convenience, an IPv6 address may be abbreviated to shorter notations by application of the following rules, where possible. 1. One or more leading zeroes from any groups of hexadecimal digits are removed; this is usually done to either all or none of the leading zeroes. For example, the group 0042 is converted to 42.
2. Consecutive sections of zeroes are replaced with a double colon (::). The double colon may only be used once in an address, as multiple uses would render the address indeterminate. RFC 5952 recommends that a double colon should not be used to denote an omitted single section of zeroes.
An example of application of these rules:
Initial address: 2001:0db8:0000:0000:0000:ff00:0042:8329
After removing all leading zeroes: 2001:db8:0:0:0:ff00:42:8329
After omitting consecutive sections of zeroes: 2001:db8::ff00:42:8329
As an IPv6 address may have more than one representation, the IETF has issued a proposed standard for representing them in text (Internet Engineering Task Force (IETF), 2013).
The DHCP package contains an Internet Systems Consortium (ISC) DHCP server. First, install the package as the superuser:
~] # yum install dhcp
Installing the DHCP package creates a file, /etc/dhcp/dhcpd.conf, which is merely an empty configuration file:
~]# cat /etc/dhcp/dhcpd.conf
#
# DHCP Server Configuration file.
# see /usr/share/doc/dhcp*/dhcpd.conf.sample
The sample configuration file can be found at /usr/share/doc/dhcp<version>/dhcpd.conf.sample.
(redhat, 2013)