How to collect device ID numbers before installing Lion Server

The first step in performing a Lion Server installation is to gather the information you will need about your Lion Server machine and your network equipment. This tells you where to look for information about the Lion Server.
There are two hardware identification numbers that are useful for logging if your network contains multiple servers: the MAC address and the serial number. If you use remote management software for multiple clients and a server, this information may help you configure that software.
The MAC address does not refer to the Macintosh operating system; It’s an acronym for Media Access Control. A MAC address is a unique hardware identifier that identifies each Ethernet port or wireless network card.
In general, if a Mac has two Ethernet ports, it will have two MAC addresses. (The exception is Xserve, which has a built-in Ethernet port that contains two MAC addresses—one used by the server processor and one used by the Xserve’s Lights Out processor.)

A MAC address takes the form of a string of two-digit characters separated by a colon, like this: 00:23:32:b5:d0:43. Apple also refers to a MAC address as an Ethernet ID.
The serial number is a unique number that identifies each Mac. A Mac can only have one serial number, other than the MAC address. All Macs list the serial number somewhere on the outer case. Many Macs also include a MAC address/Ethernet ID.
The Mac Pro’s serial number is written on the back on a label under the video ports, for example. Xserve has a withdrawal tab in the middle of the back panel.

If you can’t get to the serial number because your Mac is in a hard-to-reach location, the Mac OS X trick has been around for many years, but even some die-hard Mac fans don’t know about it: Choose Apple Menu → About This Mac. Click the Mac OS X version number twice, then it changes to the device serial number.
To get the MAC address / Ethernet ID in Mac OS X 10.6 and earlier, click the “More Information” button to start System Profiler. Remember that every Ethernet port and AirPort card has a MAC address, so be sure to specify which Ethernet ports you will use for your network. Click Network in the left pane, and the MAC address under Ethernet will be listed in the right column.