Lesson 3:Configuring a DNS Client | 70-270: MCSE Guide to Microsoft Windows XP Professional (MCSE/MCSA Guides)

There are several methods available for configuring TCP/IP name resolution on Windows XP Professional clients. The method covered in this lesson uses DNS to provide name resolution. A second method is to use a HOSTS file. For networks without access to a DNS name server, creating a HOSTS file, which is a manually maintained local file, can provide host-to-IP address and NetBIOS-to-IP name resolution for applications and services. HOSTS files can also be used in environments in which name servers are available, but not all hosts are registered, perhaps because some hosts are only available to a limited number of clients.

If there is a computer on your network that is running Windows 2000 Server and has the DNS Service installed and configured on it, you should use DNS for name resolution. This lesson shows you how to configure your computer as a DNS client.

After this lesson, you will be able to

Configure a DNS client

Estimated lesson time: 25 minutes

Because DNS is a distributed database that is used in TCP/IP networks to translate computer names to IP addresses, you must first ensure that TCP/IP is installed on a client running Windows XP Professional. Internet Protocol (TCP/IP) is installed by default during Windows XP Professional installation. Once you have confirmed that TCP/IP is installed on your client, you are ready to configure your computer as a DNS client.

To configure your computer as a DNS client, you would do the following:

Click Start, and then click Control Panel.
In the Control Panel window, click Network And Internet Connections.
In the Network And Internet Connections window, click Network Connections.
Right-click Local Area Connection and then click Properties.
Windows XP Professional displays the Local Area Connection Properties dialog box.
Click Internet Protocol (TCP/IP) and then click Properties.
Windows XP Professional displays the Internet Protocol (TCP/IP) Properties dialog box (see Figure 5.6).

Figure 5.6 Internet Protocol (TCP/IP) Properties dialog box

Configuring DNS Server Addresses

You must select one of the two following options:

Obtain DNS Server Address Automatically. If you select this option, you must have a Dynamic Host Configuration Protocol (DHCP) server available on your network to provide the IP address of a DNS server.
Use The Following DNS Server Addresses. If you select this option, you must type in the IP addresses of the DNS servers you want this client to use. You can enter a Preferred DNS Server address and an Alternate DNS Server address.

If you click Advanced and then click the DNS tab, you can set additional configurations for DNS (see Figure 5.7).

Figure 5.7 Advanced TCP/IP Settings dialog box

In the Advanced TCP/IP Settings dialog box, for the DNS Server Addresses, In Order Of Use box, you can do one of the following:

Click Add to enter additional DNS server addresses to the list of servers that service this computer to resolve DNS domain names.
Click Edit to modify the addresses listed (for example, to correct an error you made in entering an IP address).
Click Remove to delete the address of a DNS server from the list.
Click the up-pointing arrow or down-pointing arrow to change the order of the servers listed. These arrows work like the up-pointing and down-pointing arrows you use to change the binding order. The order that the addresses are listed is the order in which the servers are used. If you use the up-pointing arrow to move an address higher on the list, that server is used before all the servers listed after it. Conversely, using the down-pointing arrow to move a server lower on the list causes all servers that are listed above it to be used first to resolve DNS domain names.

Configuring DNS Query Settings

In the Advanced TCP/IP Settings dialog box, you can also configure how suffixes are added to queries.

Append Primary And Connection Specific DNS Suffixes

By default, the Append Primary And Connection Specific DNS Suffixes option is selected. This option causes the DNS resolver to append the client name to the primary domain name, as well as the domain name defined in the DNS Domain Name field of each network connection. The resolver then queries for that FQDN. If this query fails and you have specified a connection-specific DNS suffix in the DNS Suffix For This Connection text box, it causes the DNS resolver to append the client name to the name you specified there. If a DHCP server configures this connection and you do not specify a DNS suffix, a DNS suffix for the connection is assigned by an appropriately configured DHCP server. If you specify a DNS suffix, it is used instead of one assigned by a DHCP server.

The Append Parent Suffixes Of The Primary DNS Suffix check box is also selected by default. If it is selected, the DNS resolver strips off the leftmost portion of the primary DNS suffix and attempts the resulting domain name. If this fails, it continues stripping off the leftmost label and attempting the resulting domain name until only two labels remain.

Append These DNS Suffixes (In Order)

By default, the Append Primary And Connection Specific DNS Suffixes option is selected, so the Append These DNS Suffixes (In Order) option is not selected; only one of these two options can be selected at one time. This option allows you to specify a list of domains to try. The DNS resolver adds each one of these suffixes, one at a time and in the order you specified. Queries for unqualified names that are used on this computer are limited to the domains that you listed in Append These DNS Suffixes (In Order).

Register This Connection's Addresses In DNS

Selecting the Register This Connection's Addresses In DNS check box causes the computer to attempt to dynamically register the IP addresses (through DNS) of this computer with its full computer name. To view the computer name for this computer click Start, click My Computer, click View System Information, and click the Computer Name tab.

Use This Connection's DNS Suffix In DNS Registration

Selecting the Use This Connection's DNS Suffix In DNS Registration check box causes the computer to use DNS dynamic updates to register the IP addresses and the connection-specific domain name of the connection. The connection-specific name of this DNS connection is the computer name, which is the first label of the full computer name specified in the Computer Name tab located in View System Information, and the DNS suffix of this connection. If the Register This Connection's Addresses In DNS check box is selected, this registration is in addition to the DNS registration of the full computer name.

Practice: Configuring a DNS Client

After completing this practice, you will be able to configure computers running Windows XP Professional as DNS clients.

To configure a client to use the DNS Service

Click Start and then click Control Panel.
In the Control Panel window, click Network And Internet Connections.
Click Network Connections.
Right-click Local Area Connection, and then click Properties.
Click Internet Protocol (TCP/IP), and then click Properties.
In the Internet Protocol (TCP/IP) Properties dialog box, select Use The Following DNS Server Addresses.
In the Preferred DNS Server text box, type the IP address of the primary name server for this client.
If you are on a network, ask your network administrator the IP address of a DNS server you can use and type that address in the Preferred DNS Server text box. If you are not on a network or if you do not have a DNS server on your network, you can type 192.168.1.203 as the Preferred DNS Server IP address.
If there is a second name server available for this client, in the Alternate DNS Server text box, type the IP address of the second name server for this client.
If you are on a network, ask your network administrator for the IP address of a second DNS server you can use and type that address in the Alternate DNS Server text box. If you are not on a network or if you do not have a DNS server on your network, you can type 192.168.1.205 as the Alternate DNS Server IP address.

A client attempts to send its query requests to the preferred name server. If that name server is not responding, the client sends the query request to the alternate name server.

If you are going to configure several computers running Windows XP Professional as DNS clients, configure some of the clients to use the alternate name server as the preferred name server. This reduces the load on the primary server.
Click Advanced, and then in the Advanced TCP/IP Settings dialog box, click the DNS tab.
Under DNS Server Addresses, In Order Of Use, click Add.
If there is a third name server available for this client, in the TCP/IP DNS Server text box, type the IP address of the third available name server for this client.
If you are on a network, ask your network administrator for the IP address of a third DNS server you can use and type that address in the TCP/IP DNS Server text box. If you are not on a network or if you do not have a DNS server on your network, you can type 192.168.1.207 as an additional DNS Server IP address.
Click Add to add the third DNS server address and to close the TCP/IP DNS Server dialog box.
There are now three addresses in the DNS Server Addresses, In Order Of Use list box.
Click OK to close the Advanced TCP/IP Settings dialog box.
Click OK to close the Internet Protocol (TCP/IP) Properties dialog box.
Click Close to close the Local Connection Properties dialog box.
Close the Network Connections window.

Lesson Review

Here are some questions to help you determine whether you have learned enough to move on to the next lesson. If you have difficulty answering these questions, review the material in this lesson before beginning the next lesson. The answers are in Appendix A, "Questions and Answers."

What is a HOSTS file and when would you create one?
Which of the following statements about configuring a DNS client are correct? (Choose all answers that are correct.)
1. If you select the Obtain DNS Server Address Automatically option, at least one of the available DNS servers must be configured to broadcast its IP address.
2. If you select the Use The Following DNS Server Addresses, you are limiting your DNS client to being able to use only two DNS servers, the preferred DNS server and the alternate DNS server.
3. To use the Obtain DNS Server Address Automatically option, you must have a DHCP server available on your network.
4. To configure a DNS client, you use Network and Internet Connections, which is located in Control Panel.
Which of the following functions do you perform using the Advanced TCP/IP Settings dialog box? (Choose all answers that are correct.)
1. Edit the IP address of a DNS server.
2. Delete the IP address of a DNS server.
3. Enter additional IP addresses for other available DNS servers.
4. Edit the IP addresses of the DHCP servers on the network.
What does selecting the Append These DNS Suffixes (In Order) option do?

Lesson Summary

For networks without access to a DNS name server, you can manually create a HOSTS file, which provides host-to-IP address and NetBIOS-to-IP name resolution for applications and services.
In configuring a DNS client in an environment where there are DNS name servers, you can configure the client to obtain the address of the DNS server automatically from a DHCP server or you can manually enter multiple addresses for DNS servers.
In the Advanced TCP/IP Settings dialog box, you can configure how suffixes are added to queries.