DNS (Domain Naming Service) is a service that maps the names of computers on a network to their TCP/IP (Transmission Control Protocol/Internet Protocol) addresses. A PTR (Pointer) record is stored in a reverse lookup zone created on a DNS server. PTR records map known TCP/IP addresses to computer names. When a program knows the TCP/IP address of a computer and needs to find the host name of the computer, the program requests a reverse DNS lookup. The DNS server scans the list of PTR records in its reverse lookup zone for a record that maps to the TCP/IP address and returns the host name mapping to that address in the PTR record, to the requesting program. The SMTP (Simple Mail Transfer Protocol) function of Microsoft Exchange e-mail servers uses reverse lookups. Microsoft Windows servers can host DNS reverse lookup zones.
Click "Start" then select Administrative tools. Select DNS from the list of administrative tools that appears. This will open the DNS snap-in using a Microsoft management console (MMC).
Locate the name of your DNS server in the list on the left of the console. Click the check box next to the server name to expand the DNS components configured on the DNS server.
Click the check box next to the "Reverse Lookup Zones" folder. This displays the list of reverse lookup zones managed by the DNS server.
Right-click the "Reverse Lookup Zone" that you want to create the PTR record in. This will display a list of options. Select the "Other New Records" option. This opens a "Resource Record Type" window. Select "Pointer (PTR)" from the list of record types, then click "Create Record." This opens a "New Resource Record" window.
Type the TCP/IP address in the "Host IP Address" text strap. This will automatically create a Fully Qualified Domain Name (FQDN) for the record. Type the host name of the computer that maps to the TCP/IP address in the "Host name" text strap. Click "OK" to return to the "Resource Record Type" window.
Click the "Done" button to create the record in the DNS reverse lookup zone. Reverse DNS lookups for that TCP/IP address will now return the host name of the computer.
Use the "Browse" button to locate and select the computer host name in Step 5. This ensures that you will not mistype the name.