Fun with Hosting on Your Cable/DSL ---------------------------------- by toby (toby@richards.net) In 19:3, Khoder bin Hakkin wrote a wonderful article about setting up a web server on your cable or DSL service. Having done this, I noticed a few juicy tidbits of information that he left out. Port Redirection If your ISP blocks port 80 to prevent you from running a web server, then it is not necessary to use a third party web server; it is not necessary to reconfigure your web server to port 81 or any other port. Many cable/DSL routers, including the cheap ones (I've used a $70 D-Link DI-604 and a $50 Linksys EtherFast) support port redirection. From your cable/DSL router's web interface or other configuration utility, you can set up NAT so that incoming requests to port 81 (or any other port) are redirected to an internal port 80 address. In addition to disabling the preset http port forwarding, you might also have to change its internal port from 80 to something else, otherwise you might get a conflict. Dynamic DNS As you know, some cable or DSL providers give you a dynamic IP address. Therefore, you cannot associate a friendly URL (i.e., www.myhouse. com) with your cable or DSL connection. This makes it difficult to run a web page, ftp site, or other Internet services from your house. There are lots of programs and services out there that allow your computer to automatically change DNS whenever your IP address changes. However, I've had trouble finding such a program that works well with Windows (DNSQ's client works great with Linux). Recently, I found a program called Direct Update (www.directupdate.net) that does a good job. It works with lots of dynamic DNS providers. I suggest DNSQ (www.dnsq.org) because although their selection of sub-domains is poor, they are both free and reliable. Check out Direct Update's configuration screen for more choices of dynamic DNS providers. And in case you're wondering, Direct Update reports your router's IP address that it gets from your ISP, not the private IP address of the computer that it's running on. Other Services Why stop with a web server? I also run ftp services on my cable connection so that I can get files that I might need regardless of where I am. Be sure to secure any ftp folders with personal files. Telnet would be another useful service to run. E-mail might be slightly more difficult, because of the nature of MX records, but it could be done. And I must mention VNC (www.realvnc.com and www.uk.research.att.com/vnc). If you don't know about VNC already, think of it as open source PCAnywhere for Windows, Linux, Mac, and Solaris. Just install it as a service, and if you have a router, NAT port 5900. You can remote-control your home computer from anywhere by using your IP or dynamic DNS URL. If you want to run VNC on more than one computer, then just use port redirection as described above; redirect external ports like 5900, 5901, and 5902 to different internal IP addresses: 5900. The VNC client connects to these ports as host, host:l, and host:2 respectively. VNC is especially useful for family members who constantly need your computer help. No more describing what to click on and what to type over the phone. Install VNC on the computers your family and friends use and, when they need help, remote control their computers to fix the problem. I help my mom in Hawaii, grandma in L.A., and brother in Alaska this way. Be sure to also set them up with Direct Update and DNSQ (ever try to get an IP address out of your grandma?).