With Microsoft having released Windows Vista to manufacturing, the computing industry is now busy preparing for the first major Windows desktop operating system upgrade in more than five years. One of the new features of Vista that hasn’t gotten much attention is Microsoft’s new “Computer Name” feature, which extends Windows XP’s Peer Name Resolution Protocol (PNRP) service. Simply put, Computer Name allows users to identify their machine by a unique name, rather than an IP address, from anywhere on the planet.
PNRP works by extending IPv6, the new standard for identifying computers and devices on the Internet. The old IPv4 standard, identifiable by the series of four integers between 0 and 255, was designed when the Internet was much smaller, and its maximum 4.3 billion addressable devices is starting to look somewhat cramped in the modern era. IPv6 allows up to 3.4 x 1038 unique addresses, which should be enough until the nanobots take over the world and turn everything into a smooth grey slurry.
Windows Vista comes with IPv6 support built in, although not all of the Internet’s infrastructure can operate using the new protocol, including many home routers now in use. If IPv6 support is not present, Vista downshifts to IPv4 as a backup, a feature which DNS co-inventor Paul Mockapetris warned could cause a significant slowdown in Internet throughput.
Extra bandwidth issues aside, what are the advantages and disadvantages of Microsoft’s improved PNRP scheme? The company touts the ability to access your computer remotely using a unique name of your choice, without having to go through the process and expense of registering a domain name on the Internet. Some security experts, however, warn that making your computer easily accessible in this manner could set you up for all sorts of nasty hacks, particularly if bugs and holes are found in the PNRP infrastructure.
PNRP must be started from the command line, with Administration privileges. The user has the option of choosing their own name for their computer, or letting Vista create a more secure 128-bit name out of random characters. Vista will start running a PNRP service in the background, and from this point on the computer is accessible directly from any other machine running IPv6. There is no central server keeping track of these names—the system uses a peer-to-peer system where every machine knows about a few other machines at random, so it takes only a few hops to track down the Computer Name in question.
Ultimately, the usefulness of the feature will depend on how widely IPv6 is adopted. As for the security concerns, because the feature has to be enabled manually it is unlikely to become the source of a widespread outbreak. However, just as with other enabling technologies like wireless, activating a Computer Name is not without its risks. As wireless networking setups are vulnerable to brute-force password hacking, PNRP will be as well. Like many computing choices these days, it will come down to balancing convenience with security.