What is IPv6?
Why is there a need for IPv6?
What is the present status of IPv4 depletion?
What should governments do to drive the adoption of IPv6?
Can the use of Network Address Translation (NAT) resolve the IPv4 address scarcity problem instead of using IPv6?
What other benefits can IPv6 offer apart from huge address space?
What is the format of IPv6 addresses?
Why IPv6 addresses use hexadecimal and not decimal?
Is IPv6 is more secure than IPv4?
Will IPv6 introduce new security vulnerabilities?
What operating systems can support IPv6?
What are the requirements in Domain Name System (DNS) to support IPv6 implementations?
What is the current practice of IPv6 address assignment to Internet Service Providers (ISPs), corporate customers and home users?
What is the status of IPv6 deployment in Hong Kong?
I am interested in learning IPv6. Which organisations in Hong Kong can offer IPv6 technical training?
Test your IPv6 connectivity?
Other IPv6 Resources and Information
1. What is IPv6?
IP version 6 (IPv6) is a new version of the Internet Protocol, designed to replace IP version 4, the Internet Protocol that is predominantly used on the global Internet today.
2. Why is there a need for IPv6?
With a 32-bit address field, IPv4 can only provide 4.3 billion addresses which are not sufficient to meet the exponential growth of the Internet and the increasing number of end user devices. IPv6 uses a 128-bit address field which can support a total of 3.4 x 10 ^38 addresses. In terms of capacity, each person in the world can have up to 5.23 x 10 ^28 addresses to use after considering that a world population of 6.5 billion.
3. What is the present status of IPv4 depletion?
In January 2010, the Number Resource Organization (NRO), the official representative of the five Regional Internet Registries (RIRs) that oversee the allocation of Internet number resources announced that less than 10% of available IPv4 addresses remain unallocated. Given this alarming situation, NRO urged service providers, governments, enterprises and public organizations worldwide to take action in IPv6 adoption otherwise they will not be able to sustain their business growth when IPv4 addresses have completely run out.
4. What should governments do to drive the adoption of IPv6?
Governments should act as a facilitator to provide a conducive environment to the timely deployment of IPv6. Specifically, governments should consider:
a. working with the private sector and other stakeholders to increase education and awareness and reduce bottlenecks;
b. demonstrating government commitment to adoption of IPv6; and
c. seeking international co-operation and monitoring IPv6 deployment.
5. Can the use of Network Address Translation (NAT) resolve the IPv4 address scarcity problem instead of using IPv6?
In the past decade, the use of NAT has delayed the IPv4 address exhaustion. However, NAT should not be used as a long term solution. The reason is that NAT breaks end-to-end connectivity and is only suitable for a client-server application model. Other applications requiring end-to-end visibility such as peer-to-peer, VPN, VoIP and IPsec are difficult to implement since NAT stands as an intermediate node between end points. With the use of IPv6, new applications with guaranteed end-to-end visibility and security can be developed.
6. What other benefits can IPv6 offer apart from huge address space?
IPv6 is designed to improve the deficiencies of existing IPv4 protocol. The enhancements include optimized header format, improved support for extensions and options, flow labeling capability, hierarchical addressing structure, autoconfiguration, mandatory support for IPsec and mobility. Above all, increased address space remains the key benefit which is vital to the continuous growth of the Internet.
7. What is the format of IPv6 addresses?
While IPv4 addresses are written as four decimal numbers (each from 0 to 255) separated by dots such as 22.214.171.124, IPv6 addresses are written as eight groups of four hexadecimal digits (0-F), with each group separated by colons. An example is ipv6.isoc.hk which maps to the IPv6 address 2001:470:18:30a::2 in which leading zeros within each colon separated chunk can be omitted (e.g., 470 in the above address is really 0470), and a double colon represents multiple zeroes. Without those "shortcuts", the IPv6 address will be written in a long and cumbersome format which looks like 2001:0470:0018:030a:0000:0000:0000:0002.
8. Why IPv6 addresses use hexadecimal and not decimal?
Hexadecimal (base 16) is used in IPv6 because it is easier to convert between hexadecimal and binary (base 2) than it is to convert between decimal and binary.
9. Is IPv6 is more secure than IPv4?
Compared with IPv4, IPv6 does not bring any security advantages since the basic mechanism for conveying packets in the network layer remains unchanged. In fact, in today's Internet, vulnerabilities are often prevalent in the application layer but not in the network layer. Whether a network is running IPv4 or IPv6, the same level of risks will exist if vulnerabilities in applications are not duly plugged.
10. Will IPv6 introduce new security vulnerabilities?
IPv6 is not as mature as IPv4 in terms of both implementation and operational practices, and since most networks will need to run dual-stack deployments, IPv6 will likely decrease the overall security of networks by bringing more possible vulnerabilities. Overall, maintaining network security will be quite a challenging task in a dual-stack environment.
11. What operating systems can support IPv6?
Almost all releases of operating systems (OS) within the last few years have built-in support for IPv6 protocol. These include Windows Vista, Windows 7, Windows 2008 Server, MacOS X and various distributions of UNIX and Linux. Windows XP Service Pack 2 and Windows 2003 Server also have IPv6 support but is not enabled by default. For these two OS versions, IPv6 can be activated manually by "ipv6 install" in the DOS command mode.
12. What are the requirements in Domain Name System (DNS) to support IPv6 implementations ?
A new resource record "AAAA" is implemented in DNS for mapping host names to IPv6 addresses. An example is given below:
www.ipv6.ripe.net. 3600 IN AAAA 2001:610:240:22::c100:68b
As for reverse lookup, a new reverse-mapping namespace "ip6.arpa" is created. Unlike the format of addresses in AAAA records, all leading zeros must be presented so a string of 32 hexadecimal digits are used. The reverse lookup name that corresponds to the previous example is:
b.126.96.36.199.0.1.c.0.0.0.0.0.0.0.0.188.8.131.52.0.4.2.0.0.1.6.0.184.108.40.206.ip6.arpa. 3600 IN PTR www.ipv6.ripe.net.
13. What is the current practice of IPv6 address assignment to Internet Service Providers (ISPs), corporate customers and home users?
An ISP will be assigned a /32 address block from a RIR or Local Internet Registry. Within the /32 address block, the ISP can then assign a /48 address block to individual corporate customers which can support a large number of networks and millions of devices. As for home users, they will be assigned a /64 address block sufficient for building a basic home network with thousands of devices. In contrast, home users today are only given a single IPv4 address and they have to use NAT devices to build their home network.
14. What is the status of IPv6 deployment in Hong Kong?
- The Hong Kong Internet Exchange (HKIX) has supported IPv6 since March 2004 by a dual-stack approach. Currently, about 42 networks have IPv6 connections to HKIX.
- The Hong Kong Domain Name Registry can now support IPv6 glue records for the ".hk" domain names.
- Six out of nine ".hk" name servers are now accessible by IPv6.
- Local supply of IPv6 Internet access service is limited. Only a few ISPs offers IPv6 Internet connection service in Hong Kong. Other service providers are still considering the business case for providing such services.
- In December 2009, the Government enabled 231 government websites accessible by IPv6. Today, most of the Government email accounts can also receive email over IPv6.
- Hurricane Electric Incorporation has established IPv6 connection at HKIX to provide free tunnel broker, Teredo relay and 6to4 relay services to users in Hong Kong and the Asia Pacific Region.
15. I am interested in learning IPv6. Which organisations in Hong Kong can offer IPv6 technical training?
Since 2007, the Internet Society Hong Kong (ISOC-HK) has collaborated with the Asia Pacific Network Information Centre (APNIC) to offer IPv6 training courses and workshops on a regular basis. Notice will be posted in the ISOC-HK website at www.isoc.hk.
16. Test your IPv6 Connectivity?
17. Other IPv6 Resources and Information
Internet Society - World IPv6 Day:
Regional Internet Registries:
AfriNIC IPv6 Portal (Africa)
APNIC ICONS IPv6 Wiki (Asia Pacific)
ARIN IPv6 Wiki (North America)
LACNIC portal IPv6 (Latin America)
IPv6 Act Now website by RIPE NCC (Europe, the Middle East and Central Asia)
Office of the Government Chief Information Officer - IPv6 Resources