A+: Universal Naming Convention and Fully Qualified Domain Names

The Universal Naming Convention (UNC) is designed to enable users to access network resources such as folders or printers without mapping drive letters to network drives or specifying the type of device that stores the file or hosts the printer. A UNC name has the following structure in Windows:

\\servername\share name\path\filename

A typical UNC path to a document would resemble

\\Tiger1\O\NetDocuments\this_doc.doc

A typical UNC path to a shared printer on the same system would resemble

\\Tiger1\Printername

What does this mean in plain English?

• \\Tiger1 is the server.

• \O is the share name.

• \NetDocuments is the path.

• \this_doc.doc is the document.

• \Printername is the printer.

UNC enables files and printers to be accessed by the user with 32-bit Windows applications. Because only 23 drive letters (maximum) can be mapped, UNC enables network resources beyond the D–Z limits to still be accessed.

To display the UNC path to a shared folder with Windows XP, right-click the share in My Network Places (Network in Windows Vista) and select Properties. The Target field in the dialog lists the UNC path.

Some Windows applications will display the UNC path to a file even if the file was accessed through a mapped drive letter, and other Windows applications will refer to the UNC path or mapped drive letter path to the file, depending on how the file was retrieved.

Fully Qualified Domain Names (FQDNs)

TCP/IP networks that contain DNS servers often use FQDNs to refer to servers along with, or in place of, UNC names. The structure of an FQDN is

Name-of-server.name-of-domain.root-domain

For example, a server called “charley” in the informit.com domain would have an FQDN of

charley.informit.com

If you want to access the shared Docs folder on charley.informit.com, you would refer to it as

\\charley.informit.com\Docs

You can also use the IP address of the server in place of the servername. If 192.10.8.22 is the IP address of charley.informit.com, you can access the Docs folder with the following statement:

\\192.10.8.22\Docs

You can use either UNCs or FQDN along with the Net command-line utility to view or map drive letters to shared folders.