IPV6 The Next Generation

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Solaris™ Operating Environment Boot Camp
By David Rhodes, Dominic Butler
Table of Contents
Chapter 11.  Connecting to the Local Area Network


IPV6The Next Generation

While IP Version 6 (IPV6) is really beyond the scope of this book, this section will provide a very brief glimpse into what it is and one of the main driving forces behind its creationthe pending lack of available IP addresses.

All the IP addresses we have used up to now have been based on a 32-bit value, separated into four eight-bit fields. These are known as IP Version 4 (IPV4) addresses. One of the limitations we have with this protocol is that we only have around four billion addresses available (even less when we take network and broadcast addresses into account).

Nowadays, many more computers are being connected to the Internet than were first expected, each of them requiring an IP address. Coupled with this, many other types of hardware, such as microwaves, toasters and cars, are being assigned addresses and connected to networks in a way that the designers of IP could not have imagined.

It became obvious a few years ago that soon we would run out of IP addresses. To get around this problem, the next generation of the IP protocol was designed. This is known as IPV6 and is based on 128 bits, which allows a theoretical maximum of 340,282,366,920,938,463,463,374,607,431,768,211,456 addresses to be defined. Obviously this is quite a lot, which hopefully means we shouldn't run out in the near future!

IPV6 Addresses

An IPV6 address will generally be shown as a group of hexadecimal values, rather than the numbers we are familiar with. The separator between the groups has also altered, and is now shown as a colon (:) rather than the familiar dot (.). For example, our current 32-bit address for hydrogen (192.168.1.2) may become something like the following:

 192.168.1.123.54.68.168.98.234.12.54.29.12.56.113.1 

whereas a typical IPV6 address may look like the following:

 A00E:0023:0000:0000:0000:0083:125C:ABCD 

Fortunately, the designers have recognized that this is still a bit of a mouthful, so there are a few shortcuts that we can use. First, we can drop any preceding zeros, and secondly, we can replace a 16-bit zero value number with a double colon. This means that the above address may now be written as follows:

 A00E:23::83:125C:ABCD 

Solaris uses a file named /etc/hostname6.<interface name> to provide address details for the interface. IPV6 includes autodiscovery within its standards, which means that an interface can determine its own IP address simply by querying its local router. This is the norm. Assuming the interface card is an "hme" type, this means that all that's required to set the simplest (default) address is to create an empty /etc/hostname6.hme0 file.

Once set, ifconfig will report the interface and show something similar to the following:

 hydrogen# ifconfig -a <lines removed for clarity> hfe0: flags=2000841<UP,RUNNING,MULTICAST,IPv6> mtu 1500 index 2         ether 8:0:20:aa:bb:cc         inet6 fe80::203:baff:fe08:ad6f/10 hydrogen# 

Using ping to test the interface would produce something similar to the following:

 hydrogen# ping -A inet6 fe80::203:baff:fe08:ad6f fe80::203:baff:fe08:ad6f is alive hydrogen# 

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    Solaris Operating Environment Boot Camp
    Solaris Operating Environment Boot Camp
    ISBN: 0130342874
    EAN: 2147483647
    Year: 2002
    Pages: 301

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