Useless?

In the early 1980s, I had a 300 baud modem. From a business point of view, it was just about useless. Our local BBS sysop, Greg Corson of “The Connection”, offered turnkey BBS systems to businesses, so that employees could have mail, discussion and file transfer, but he was way ahead of his time. Businesses took a pointless detour to fax machines before they understood the power of offering BBS-like services to everyone.

Like that old modem, all new networking technologies look useless—until enough people get on them. Then, well, it's called a “network effect” for a reason.

So what's the “useless” technology to play with today? IPv6, the next version of the Internet Protocol. You won't find news and business sites using it; you can't send most people mail on it; you can't call up the phone or cable company and get it, and if you put up an IPv6 web site, Google won't crawl it. On the other hand, IPv6 has enough unique IP addresses (2128 of them) that no matter what kind of internet service you have, you can have a static address of your very own.

You can really get that address and do something with it, too. Viagénie, a Canadian company, sponsors freenet6.net, an easy-to-use service to tunnel IPv6 over your existing net connection. I worked through Peter Todd's article on page 64, and it took me less time to finish and “ping6” his IPv6 box, than to read the article. And I read fast.

You can do more with IPv6 than just ping Peter's box—Ibrahim Haddad and David Gordon take a look at how well Apache handles IPv6 traffic on page 86. And once you're on IPv6 with a static address that's all yours, you can start to learn more.

Another great network project is a VPN to link sites securely over an existing connection. Be a hero at work when you replace an expensive leased line or proprietary VPN box with FreeS/WAN, using Mick Bauer's instructions on page 30. How much did you pay for Linux Journal again? We're such a bargain.

Software you write probably calls read() and write() to get data from disk and send it to the network, or vice versa. But behind the scenes, the kernel is copying the data for you. Can you speed things up? Dragan Stancevic takes you along the path to zero copies and explains the sendfile() system call along the way, on page 48.

Guylhem Aznar has written two articles for our web site on hot new apps for the Linux-based Zaurus PDA, and this month he's on page 38 with recommended software, and some key hardware, to make your Zaurus (you do have one, right?) more useful than ever.

There's plenty of other good stuff this month too. Java doesn't have to be just a bytecode language—you can compile it like C (page 74). And when I make an SSH connection across a flaky network, I want to be able to pick up where I got thrown off. The screen program lets you do that and more, on page 80.

Finally, the cover. Robin Rowe has written us another Linux movie article, this one about the latest Star Trek movie. Linux Journal doesn't get to see the Linux movies before everyone else, but do you really think Starfleet gets by with only 232 IP addresses?