Network Information You Need before Lion Server Installation - dummies

Network Information You Need before Lion Server Installation

By John Rizzo

During the installation and setup process, you may be asked for variety of numbers that identify your network and the server’s role in it. You may need this information for each network port you’ll use, though some of these numbers may be supplied automatically if your server is connected to the network during installation. Here’s a description:

  • IP address: If you’re upgrading Snow Leopard or Lion client to Lion Server, set the IP address before starting the installation.

    Every network port (including wireless) on a computer on the network has an IP address that identifies it to other computers. For client computers, the IP address is usually set automatically via DHCP (Dynamic Host Configuration Protocol).

    But servers need an IP address that never changes in order for the network to find them, so it’s best to manually assign an IP address to the server, called static IP addressing. On a Mac, you set the IP address in the Network pane of System Preferences.

    The IP address is four numbers separated by periods, such as Each number can be from 0 through 255. See the “Rules for IP addressing” sidebar for more details on selecting IP addresses.

  • Subnet mask: This number appears in the form of four numbers separated by the dots that are often 255 or 0, such as Use a different subnet mask for each Ethernet port. The computers connected to a server’s Ethernet port are on a subnet. The subnet mask limits the size of the subnet. The subnet mask can also be set automatically via DHCP.

  • Router: You may need the IP address of the hardware that moves data between local subnetworks and the Internet, such as an AirPort base station. The router might also have a DHCP server that automatically assigns IP addresses to your computers. If you’re setting up services that will be visible to the Internet, you may need to configure port forwarding on the router.

    If you have your Mac connected to the network during installation, the installer software may detect the router and provide its IP address.

  • DNS servers: Before setting up your Mac server, you need to know if you have domain name services (DNS) servers on your network or provided by your Internet service provider. Otherwise, you can disrupt your server and parts of the rest of the network. You may need to record the IP addresses of DNS servers, and you should record any domain names used.

    The domain name comes in the form of or The DNS server translates domain names to IP addresses. If you configure this manually, you’ll obtain the IP address of the DNS from your Internet service provider. This is one of the more important settings in getting your server to work properly.

  • Computer name: The installation procedure will create a computer name, which you can change. This is a uniquely Macintosh network name that identifies Macs to other Macs, as well as Windows running Bonjour for Windows. On Mac clients, this name will appear in the Finder sidebars and in various dialogs. You can also set the computer name in the Sharing pane of System Preferences.

    A Mac computer name can be 63 characters or less. Use Roman characters except for the equal sign (=), the colon (:), or the at sign (@). Spaces are okay.

    Users find it helpful if the name has some significance, such as Computer Lab Server. A computer name translates into a local network name, such as computer-lab-server.local. The local network name is used only on the local subnet, in addition to a DNS name of the server.