Section 9.7. Web Servers

9.7. Web Servers

If you want to surf the Internet over IPv6, you need web servers and a browser that support IPv6.

There are different HTTP servers that already support IPv6. Probably the most common one is Apache, which has supported IPv6 since version 2. Version 1.3 can be patched to support IPv6. Whichever HTTP server you use, you must be able to configure it to listen on the HTTP port (usually 80) over IPv6. If you are using proxy servers, you need to make sure that they are enabled for IPv6, too.

If you are looking for references on how to set up Apache 2 on Linux, refer to the web site of the Linux Documentation Project (LDP) at http://www.tldp.org. There is one chapter that explains configuration of different daemons, including BIND (named) and Apache 2 (httpd2).

9.7.1. Browser Support

To browse IPv6 sites, you need a browser that sends out DNS requests for AAAA records and DNS to return an IPv6 address for the name of the web server you are trying to access. In some cases, you can also enter a literal IPv6 address (described in RFC 2732) in your browser. It has the format http://[2001:DB8:4179::836B:4179]. Some browsers can use this format. Internet Explorer, included in Windows XP, no longer supports literal IPv6 addresses; however, other browsers on Windows XP can use literal addresses. As an aside, consider how the vast majority of nontechnical Internet users would react or even adapt to having to use the URL cited above to surf the Internet. The colon hexadecimal format of IPv6 addresses will certainly be cumbersome for most users and is very error-prone. This is yet another illustration of the value DNS brings to IPv6 deployments.

If your browser is configured for a proxy server that is not enabled for IPv6, it cannot browse local or remote IPv6 web sites. In this case, you will have to disable the use of the proxy for your IPv6 trips.

If you want to experiment, you can find a list of IPv6-accessible web sites at http://www.ipv6.org/v6-www.html. Many of these sites are dual-stack; some can be reached only over IPv6. For Linux users, the best link will probably be http://www.bieringer.de/linux/IPv6/status. If you want to test your IPv6 connectivity, try our IPv6-only web site at http://ipv6.sunny.ch and say hi when you get there!

9.7.2. Proxy Support and Scenarios

One important goal in a heterogeneous network is to make all services available over as many channels as possible. The question of whether a corporate network will use IPv4 or IPv6 in the near future is the wrong question. Reality for the coming years will be that people/customers use both protocols. In the Internet, there will be web sites available only over IPv4, others available only over IPv6, and hopefully most of them available over both protocols. Internet surfers will use one or the other, or in some cases both protocols. If you want to offer services or a web site to the whole community, you will not get around making it available over both protocols.

In the case of a web site, the easiest way to go may be dual-stack. There may be cases where the addition of IPv6 to your web server cannot be accomplished within a short time for different reasons. In this case, proxies can help you fulfill the protocol requirement.

Proxies can be used in different ways:

• Your hosts in the corporate network are IPv4-only, but you want them to be able to view IPv6-only web sites also. Configure your proxy dual-stack to the outside world, and let your internal users view IPv6 content over IPv4. Obviously this works the other way, toolet IPv6-only clients view IPv4 content over IPv6 through the dual-stack proxy.

• Your web site is IPv4-only for the moment, and you currently cannot add IPv6 support. But you want IPv6 Internet users to be able to view it. Set up a proxy in front of the web server that is dual-stacked. Internet users can use IPv6 to view content on your IPv4-only web server.

If you cannot set up a proxy to provide your IPv4 web site over IPv6 for any reason, use http://www.6gate.com. This is the simplest (and free) way to immediately add IPv6 access to your web site. The only thing it requires is a DNS entry. But don't forget, these are temporary solutions. The goal is to configure your web site to be dual-stack as soon as possible.

The next chapter describes integration and transition mechanisms and scenarios that allow for a smooth, step-by-step introduction of IPv6 into your network.