IPv6: Internet Protocol version 6, frequently asked questions

WIDE Project, IPv6 working group

$Id: v6faq.html,v 1.6 1997/10/24 03:05:22 itojun Exp $

in Japanese

NOTE: this document is targetted to general public, not to implementers/designers of IPv6. If you have any comments, send e-mail to itojun@itojun.org.


Q: What is different between IPng and IPv6? Are they different or same?

A: In short, they are different. IPng is rather a conceptual name for "revised IP". There's no specific protocol called IPng, I believe. IPv6 is a name of a protocol, which was choosed in IPng protocol competition from several candidates.

(see chapter 1 in huitema's book, for details)

Q: Would like to have current status and movements. Give me some pointers.

A: here are good starting points:
IETF ipng working group homepage
WIDE IPv6 working group homepage
Christian Huitema, "IPv6: the new internet protocol", Prentice hall.

Q: What is the status of IPv6 spec? Has it been fixed?

A: Partly yes, partly no. Basic specs are out as RFC (Request For Comments) documents. Related upper-layer specs are now being discussed at IETF ipng working group, and some of the documents are accessible as internet-draft. Proceed to playground.sun.com for details.

Q: What are the major advantages of IPv6?


Q: When will the IPv4 address be sold out?

A: By estimation, year 2010.

Q: How soon the IPv6 address space will run out?

A: (open question)

Q: What is "6bone"?

A: The word "6bone" stands for "IPv6 backbone". The 6bone is experimental worldwide network for testing interconnectivity of IPv6 implementations, checking if IPv6 really works well or not in actual situation, and so forth. The world 6bone is made up by several regional 6bones. For example, there's a 6bone for Japan region called the WIDE 6bone, which is connected to the world 6bone. Although most of the regional 6bones are made possible by using IPv6-over-v4 tunnelling technology, some part of them are made of IPv6-dedicated leased line. (one of them is the WIDE 6bone operated by WIDE project in Japan)

Q: Features of IPv6 has been added to IPv4, as optional feature such as DHCP. Why do we need to move to IPv6?

A: It is a problem that thease features are optional for IPv4, and it is very important to include features of IPv6 into the basic spec. If you don't see why, imagine the following story: You are very novice user of the internet, who can hardly do ifconfig or routing setup. You carry along your laptop, and visited some university for presentation. Just after you connected your laptop to the local network, the chairman said that there is no DHCP server available in the university, and administrator took a day-off.

Q: Why NAT is not enough to compete with address space problems?

A: First of all, IPv6 is not only address space expansion. It is more than that. IPv4 has been used for more than 20 years, and there are various gap and strain found between spec sheet and actual usage. IPv6 tries to include technologies that are up-to-date, and inevitable for 21st century.

Also, there are many trials to interconnect home electronic devices such as washing machines, TV box, audio set, elevators and so forth, by using internet protocols. It would be very hard to follow this trend with NAT only. We need new IP protocol.

Q: Are there any killer-applications for IPv6?

A: Although almost everything that are implemented on IPv4 were ported onto IPv6, we think we do not have killer-application very specific to IPv6. We will see that after IPv6 has deployed well. We have to start by porting DOOM and Netscape onto IPv6 :-)

Q: Why it is IPv6, not IPv5?

A: The version number "5" has already been used for ST-II protocol.


Q: When will the IPv6 products be released?

A: Very few companies already released IPv6 products. It is rumored that we will see some products in early 1997.

Q: Can I use IPv6 on my Windoze box?

A: Yes, some venders are working on that. Proceed to playground.sun.com for details.

Q: Can I use IPv6 on my Macintosh?

A: Yes, some venders are working on that. Proceed to playground.sun.com for details.

Q: I would like to try IPv6 kernels.

Proceed to playground.sun.com. Some free implementations are pointed from there.


Q: When will we have to move from IPv4 to IPv6?

A: IPv6 will first be incorporated into the currently existing internet, gradually from backbone part of the internet. I think you will never notice the transition of backbone.

Transition timing of your organization, your console machine, is not very easy to forecast. It depends on product release timings, configuration of your site, transition policy of your site, and so forth.

Q: How IPv6 host communicate with existing IPv4 hosts?

A: For first years of IPv6, IPv6 host must be able to speak IPv4 hosts. Therefore, the IPv6/v4 host will communicate by IPv4 with IPv4 hosts, and by IPv6 with IPv6 (to be precise, IPv6/v4) hosts.

Q: I bought bunch of routers today. Can I use IPv6 with there routers, when IPv6 has deployed?

A: IPv6 can be implemented as software, just like IPv4 was. You can ask your dealer for firmware update.

Q: How can I switch to IPv6?

A: If you are not implementer, wait for products to come out. Otherwise, you might want to proceed to playground.sun.com for freely available implementations.

Q: Are there any IPv6 internet connectivity providers?

A: Not yet I think...


Q: There is a boy-band called "v6" is there in Japan. Is there any relationship?

A: No. Presumably, they were named after IPv6:-)