AboutCarolyn Meinel Expertise I cover Windows, Unix, TCP/IP and Ethernet security questions. I do not cover Mac, Palm Pilot, or other networking issues.
Experience Books by Carolyn Meinel: wrote a chapter for The Hacking of America book (see http://www.amazon.com/exec/obidos/ASIN/1567204600/happyhacker)
My article Code Red for the Web for Scientific American was reprinted in the book Best American Science Writing 2002 (see http://www.amazon.com/exec/obidos/ASIN/0060936509/happyhacker). My book The Happy Hacker: A Guide to Mostly Harmless Hacking is now in 4th edition with a Japanese edition (see http://happyhacker.org/hhbook/).
Question I have a "dumb" question. We are getting an installation at our office from a company called Logix. They compete with CBeyond in taking care of phone and internet services. Now one of Logix' selling point was that we can have up to 13 static IP addresses. Can you tell me what the difference is between a static and non-static IP address - and why I would want the static IPs? Can they be used for computers and printers or is just for the PCs?
Thank you,
Landon
Answer A static IP address is useful if you want a computer to run a service that people outside your business network can reach by using the Internet. For example, you could use a static IP for a webserver running on one of your business computers instead of having to pay a web farm to host your website. Another use of static IP addresses -- but less common -- is if you need to log into a remote computer that has a strong firewall. The person running that remote computer could set up the firewall to only allow someone using your static address to log into your account on that computer.
On the other hand, having static IP addresses can make it slightly easier for the bad guys to break in, especially if you run a webserver on one of them, or any other service that people can reach over the Internet. It can be quite difficult to protect your webserver, especially if it is running Windows. And then, once someone has broken into your webserver, from there, by being inside your local area network, it becomes super easy to break into all your other computers.
In conclusion, if you are confident of the security expertise in your company and want to offer services via the Internet to the general public, static IPs are great. But for most companies, they aren't a good idea.
