ENT2001: How to Create a Host File in Mac OS X

When you are using either Microsoft Entourage or Microsoft Outlook Express with Mac OS X, you may need to use a hosts file to provide address resolution to an Internet messaging server that is using the TCP/IP protocol. This article describes how to create a hosts file with Mac OS X.

NOTE: The use of the file name "hosts" in lower case in this article is different from its use in the Microsoft Windows NT implementation where the file name is in all upper case. This is because of the Unix convention for file names.

A hosts file can sometimes be required to connect to an Internet standards-based messaging server by using a "friendly" or fully qualified domain name (FQDN). Without the services provided by a hosts file, you may not be able to connect to the server except by relying on the IP address of the server.

NOTE: The following detailed steps assume that you have appropriate permissions and are logged on as the Administrator of the Macintosh to create or change a hosts file. For complete help on the role of the Administrator in Mac OS X, open Mac Help, and then type administrator in the Search box.

To create a host file with Mac OS X, follow these steps:

1. Open the /Applications/Utilities folder path, and then double-click NetInfo Manager.
2. In the Directory Browser, click the /machines directory. On the Domain menu, click Security, and then click Authenticate. You may be prompted to enter your administrator password. If Deauthenticate appears on the submenu, administrative permissions are already applied.
3. On the Directory menu, click New Subdirectory. A new item labeled new_directory appears.
4. In the Value(s) column of the lower window, double-click new_directory, and then type the name of the server to which you want to link an IP address.
5. On the Directory menu, click New Property, and then replace new_property by typing ip_address.
6. On the Directory menu, click New Value.
7. Replace new_value with the IP address of the server to which you want to connect.
8. On the Domain menu, click Save.
9. Click Update this copy, and then quit NetInfo Manager.

To test your connection, open the /Applications/Utilities folder path, and then double-click Network Utility. Click the Ping tab, and then type the name of the server that you defined in the previous procedure. Click Ping.