Configuring DNS part2

Name Servers

Name Servers specify all name servers for a particular domain. You set up all primary and secondary name servers through this record.

To create a Name Server, follow these steps:

Select DNS from the Administrative Tools folder to open the DNS console.Expand the Forward Lookup Zone.Right-click on the appropriate domain and choose Properties (Figure N).Select the Name Servers tab and click Add.Enter the appropriate FQDN Server name and IP address of the DNS server you want to add.

Figure N

Name Server

Host (A) records

A Host (A) record maps a host name to an IP address. These records help you easily identify another server in a forward lookup zone. Host records improve query performance in multiple-zone environments, and you can also create a Pointer (PTR) record at the same time. A PTR record resolves an IP address to a host name.

To create a Host record:

Select DNS from the Administrative Tools folder to open the DNS console.Expand the Forward Lookup Zone and click on the folder representing your domain.From the Action menu, select New Host.Enter the Name and IP Address of the host you are creating (Figure O).Select the Create Associated Pointer (PTR) Record check box if you want to create the PTR record at the same time. Otherwise, you can create it later.Click the Add Host button.

Figure O

A Host (A) record

Pointer (PTR) records

A Pointer (PTR) record creates the appropriate entry in the reverse lookup zone for reverse queries. As you saw in Figure H, you have the option of creating a PTR record when creating a Host record. If you did not choose to create your PTR record at that time, you can do it at any point.

To create a PTR record:

Select DNS from the Administrative Tools folder to open the DNS console.Choose the reverse lookup zone where you want your PTR record created.From the Action menu, select New Pointer (Figure P).Enter the Host IP Number and Host Name.Click OK.

Figure P

New Pointer

Canonical Name (CNAME) or Alias records

A Canonical Name (CNAME) or Alias record allows a DNS server to have multiple names for a single host. For example, an Alias record can have several records that point to a single server in your environment. This is a common approach if you have both your Web server and your mail server running on the same machine.

To create a DNS Alias:

Select DNS from the Administrative Tools folder to open the DNS console.Expand the Forward Lookup Zone and highlight the folder representing your domain.From the Action menu, select New Alias.Enter your Alias Name (Figure Q).Enter the fully qualified domain name (FQDN).Click OK.

Figure Q

Alias Name

Mail Exchange (MX) records

Mail Exchange records help you identify mail servers within a zone in your DNS database. With this feature, you can prioritize which mail servers will receive the highest priority. Creating MX records will help you keep track of the location of all of your mail servers.

To create a Mail Exchange (MX) record:

Select DNS from the Administrative Tools folder to open the DNS console.Expand the Forward Lookup Zone and highlight the folder representing your domain.From the Action menu, select New Mail Exchanger.Enter the Host Or Domain (Figure R).Enter the Mail Server and Mail Server Priority.Click OK.

Figure R

Host or Domain

Other new records

You can create many other types of records. For a complete description, choose Action | Other New Records from the DNS console (Figure S). Select the record of your choice and view the description.

Figure S

Create records from the DNS console

Troubleshooting DNS servers

When troubleshooting DNS servers, the nslookuputility will become your best friend. This utility is easy to use and very versatile. It's a command-line utility that is included within Windows 2008. With nslookup, you can perform query testing of your DNS servers. This information is useful in troubleshooting name resolution problems and debugging other server-related problems. You can access nslookup (Figure T) right from the DNS console.

Figure T