DHCP and Apache

As you remember, if your Internet connection uses DHCP to get its IP address, then you need to use dynamic DNS to get the correct Internet DNS entry for your Web server. If your Web server and firewall are different machines, then you probably also need to set up port forwarding for your Web traffic to reach the Web server correctly. (Chapter 19 explains port forwarding, as well.)

DHCP on your protected home network is different. In the book's sample topology, the Web server lives on the 192.168.1.0 home network protected by a firewall. The firewall uses NAT and port forwarding to pass Internet traffic on to the Web server. Remember that the IP address of your Web server can change if it gets its IP address using DHCP. This could cause your firewall port forwarding, not dynamic DNS, to break.

In this case, I recommend that your Web server on the 192.168.1.0 network uses a fixed, or static IP address that is outside of the range of the DHCP server to prevent you from having this problem.