of debate and analysis with the design
of a new, extended address format
called IPv6. (IPv5 was an experiment in
stream applications that did not scale
and was abandoned.) IPv6 had a small
number of new features and a format
intended to expedite processing, but
its principal advantage was 128 bits
each of source and destination host addresses. This is enough for 340 trillion
trillion trillion addresses—enough to
last for the foreseeable future.
The IPv6 format is not backwards
compatible with IPv4 since an IPv4-
only host does not have the 128 bits
of address space needed to refer to an
IPv6-only destination. It is therefore
necessary to implement a dual-stack
design that allows hosts to speak to either protocol for the period that both
are in use. Eventually, address space
will not be available for additional IPv4
hosts, and IPv6-only hosts will become
necessary. Hopefully, ISPs will be able
to implement IPv6 support before the
actual exhaustion of IPv4 addresses,
but it will be necessary to allow for
dual-mode operation for some years to
come.
World IPv6 Day is scheduled for
June 8, 2011, at which time as many
ISPs as are willing and able will turn
on their IPv6 support to allow end users and servers to test the new protocol
on a global scale for a day. The move
to IPv6 is one of the most significant
changes to the Internet architecture
since it was standardized in the late
1970s and early 1980s. It will take dedicated effort by many to ensure that users, servers, and Internet service and
access providers are properly equipped
to manage concurrent operation of the
old and new protocols.
Here, Thomas Limoncelli considers steps that can be taken to achieve
this objective.
strategies of organizations that are
making the transition. The strategies
that work tend to be those that focus
on specific applications or Web sites
rather than trying to convert an entire
organization.
The biggest decision for many organizations is simply knowing where to
begin. In this article, I consider three
possible strategies.
The first scenario we present is a
cautionary tale against what might be
your first instinct. Though fictional,
we’ve seen this story played out in various forms. The other two examples
have proven to be more successful
approaches. Knowing this, we would
offer the following advice to a business contemplating the transition to
IPv6: start with a small, well-defined
project that has obvious value to the
business.
someday the u.s.
will run out
of three-digit
telephone area
codes and
will be forced
to add a digit. as
Vint Cerf explained,
the internet is facing
a similar situation.
—Vinton G. Cerf
strategies for moving to iPv6
Someday the U.S. will run out of three-digit telephone area codes and will be
forced to add a digit. As Vint Cerf explained, the Internet is facing a similar situation with its address structure.
Often predicted and long ignored, the
problem is now real. We have run out
of 32-bit IP addresses (IPv4) and are
moving to the 128-bit address format
of IPv6. This section looks at some
story 1: “upgrade everything!”
While having a grand plan of upgrading everything is noble and well intentioned, it is a mistake to think this is
a good first experiment. There is rarely
any obvious value to it (annoys management), it is potentially biting off
more than you can chew (annoys you),
and mistakes affect people that you
have to see in the cafeteria every day
(annoys coworkers).
This strategy usually happens something like this: someone runs into the
boss’s office and says, “Help! Help! We
have to convert everything to IPv6.”
This means converting the network
equipment, Domain Name System
(DNS), Dynamic Host Configuration
Protocol (DHCP) system, applications,
clients, desktops, servers. It’s a huge
project that will touch every device on
the network.
These people sound like Chicken
Little claiming the sky is falling.
These people are thrown out of the
boss’s office.
A better approach is to go to the
boss and say, “There’s one specific
thing I want to do with IPv6. Here’s
why it will help the company.”
These people sound focused and
determined. They usually get funding.
Little does the boss realize this
“one specific thing” requires touching
many dependencies. These include
the network equipment, DNS, DHCP,
and so on—yes, the same list of things