I love everything about my MacBook Pro, but for some reason it does not like to share its screen. It appears under the "Shared" section of the sidebar in Finder, and file sharing works perfectly, but for some reason screen sharing won't work. The "Connecting To 'MacBookPro'" panel will pop up and then disappear a few moments later (as if it is about to connect), but at least 90% of the time no screen sharing window appears.

Fellow TUAW writer Aron Trimble suggested that I go into Finder and try "Go > Connect to Server" and then put in "vnc://10.0.x.x" (where 10.0.x.x is my MacBook Pro's IP address). That worked immediately, and every time.

This confirmed that it wasn't a firewall setting (Screen Sharing is explicitly on) or trouble accessing the MacBook Pro over the LAN (file sharing already worked perfectly). For some reason the screen sharing connection was just not being made over Bonjour.

The only drawback to this direct-IP method is that my network, like most, uses dynamic addresses with DHCP, meaning that the IP addresses change from time to time, especially on a network with multiple devices which are not always turned on. My first thought was to create a static IP for the MacBook Pro in System Preferences > Network, but then I realized that my office LAN uses IPs which start with 192.168.x.x. I could create a new network "Location" but that would also involve manually switching it back and forth, or using a third-party program.

What I really needed was a way to make sure that my MacBook Pro is given the same IP every time it connects to my home LAN. Fortunately, Apple's Airport Extreme will allow me to do just that using DHCP Reservations.

A DHCP Reservation tells the Airport Extreme to reserve a certain IP address for certain computers, as determined either by a "DHCP Client ID" or the computer's MAC address. A DHCP Client ID is easier to remember than a MAC address, but the MAC address will never change unless you swap out the logic board or Airport card of your Mac. I'll show you how to set it up using either method.