IPv6: time to change?

Advantages and supported applications

Advantages of IPv6
IPv6 provides for a 128-bit address space, which will exponentially increase the number of available public IP addresses.

However, IPv6 offers other improvements over IPv4:

• It supports IPsec, for better security when sending data across a TCP/IP network.
• It supports Quality of Service (QoS), for better transmission of real time, high-bandwidth applications such as videoconferencing and voice over IP.
• It is more efficient; header overhead is minimised, and backbone routers require smaller routing tables.
• Configuration is easier; both stateful addressing (where addresses are automatically assigned by a DHCP server) and stateless addressing (use of local-link auto configuration without DHCP) are supported.

Currently supported applications
The majority of applications supporting IPv6 belong to the Linux/UNIX space. Though more are appearing daily, that list includes:

1. DNS

• BIND 9.2.0: The new version of BIND uses A6 records to map a domain name to an IPv6 address and offers IPv6 transport of packets
• Totd: This lightweight DNS proxy nameserver supports IPv6.
• IPv6 transport for BIND 8: This is a patch for BIND 8.2.3 that helps resolvers talk to nameservers using IPv6.

2. Firewalls

• IPFilter: A software package that supports IPv6 filtering.
• IPFW: This IPv6-aware IPFW tool is included within the FreeBSD 4.0 release.

3. FTP

• LFTP: This FTP client supports IPv6.
• NcFTP (Windows): This is a robust IPv6 FTP client for Windows.

4.IPsec

• IPv6 FreeS/WAN for Linux: This prototype IPsec implementation was developed by IABG as part of the 6INIT project.

5. Mail

• Exim: This mail transfer agent offers built-in IPv6 support.
• Qmail: IPv6 support is available through the v1.03 patch by Kazunori Fujiwara
• Public Sendmail: Version 8.10 of this mail product officially supports IPv6.
• Fetchmail: This mail utility supports both IPv6 and IPsec

6. Monitoring tools

• ASpath-tree: Use this tool on an IPv6 site to monitor BGP4+ routing.

7. Web servers and clients

• Apache (Linux): This release of the Apache Web server for Linux has built-in IPv6 support.
• Apache 2.0.x: This beta code of Apache 2.0 supports IPv6.

Executive summary

• The world will run out of IPv4 addresses during this decade. IPv6 can cope with the anticipated massive expansion in demand for addresses for mobile devices and embedded systems.
• Some countries are already very short of IPv4 addresses, and they will most likely lead the transition to IPv6.
• IPv6 mandates encryption and source authentication in every implementation.
• IPv6 provides schemes for automatically generating unique addresses without manual intervention. This is especially important for mobile devices that connect to different networks at different times.
• Major operating systems and router vendors already support IPv6. Applications that store IP addresses internally will require upgrades.
• Don't rush into IPv6. Few organisations have any pressing need to start making the change yet.

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