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Configuring Network Registrar

Configuring Network Registrar

Network Registrar consists of modular software servers. You can configure DNS servers, DHCP servers, or both types of servers. If you want to run dynamic DNS update, you must configure both a DNS server and a DHCP server.

Note The term server can be used for both physical machines and for software applications. This guide uses the term host to refer to the physical machine and server to refer to the software application. If you choose to run both DNS and DHCP, you can install and run them on the same physical machine. In that case, one physical server is running two software servers.

This chapter describes the following:
Note If you need additional help, you can refer to the online help, which you can access from the Help command in Network Registrar. For specific information about fields in dialog boxes, you can use the What's This help, which you can access by clicking the ? and then placing it over the field in question. For more detailed information about Network Registrar, see the Network Registrar GUI User's Guide.

Configuring Your DNS Server

Your Domain Name System (DNS) Server is actually a database of information about the hosts within the domain. This database allows computers to share information about computer names and addresses over the Internet. In order to configure a correctly functioning DNS server, you need to create the following items:

You do not need to create a loopback zone because Network Registrar automatically creates one. A loopback zone is a reverse zone that enables a host to resolve the loopback address (127.0.0.1) to the name localhost. The loopback address is used by the host to enable it to direct network traffic to itself.

Configuring a Zone's Primary Name Server

Programs that store information about the domain name space are called name servers. Name servers usually have complete information about some part of the domain namespace, called the zone.

Note A zone is a delegation point in the DNS tree hierarchy. It contains all the names from a certain point downward except for those names that have been delegated to other zones. A zone defines the contents of a contiguous section of the domain space, usually bounded by administrative boundaries. Each zone has configuration data that are composed of entries called Resource Records.

A particular server can be primary for some zones and secondary for some other zones. It can be a caching server too---all at the same time. The terms primary name server and secondary name server are meaningful in relation to a particular zone. For any particular zone, there is one primary server that learns zone contents from a configuration database, and zero or more secondary servers that learn zone contents by zone transfers from another server.

You can create a primary name server manually or you can create one by populating it with the contents of your existing BIND zone file.

Manually Populating a Primary Name Server

Step 1 From the Server Manager window, select the DNS server, for example DNS@localhost. See Figure 2-1.


Figure 2-1: Server Manager Window

Step 2 Click the Add toolbar button to display the Add Zone dialog box.

Step 3 In the Name field, enter the primary zone's domain name. In the example shown in Figure 2-2, the zone is called example.com. (you need to end the name with a period).


Figure 2-2: Add Zone Dialog Box

Step 4 Click the Primary button.

Step 5 Click OK.

Step 6 From the Add Primary DNS Zone dialog box, click the SOA (Start of Authority) tab. See Figure 2-3.


Figure 2-3: Start of Authority Tab

Step 7 In the Contact email address field, enter the e-mail address of the administrator. Remember to use "." instead of "@."

Step 8 In the Name of primary server field, enter the name of the primary server.

Use either the host name (ns) or the full name. If you use the full name, such as ns.example.com., remember to end the name with a period.

Step 9 In the remaining fields, enter the appropriate values for the various times or accept the defaults.

Step 10 Click the Name Servers tab. See Figure 2-4.


Figure 2-4: Name Servers Tab

Step 11 Enter the authoritative servers for this zone that are registered authorities with InterNIC.

Use either the host name (ns) or the full name, ns.example.com. If you use the full name, remember to end the name with a period.

Step 12 Enter the TTL value or accept the default. The - (dash) in the TTL field means use the default value.

Step 13 Click the Hosts tab. See Figure 2-5.


Figure 2-5: Hosts Tab

Step 14 Click Add to display the Add Host dialog box. See Figure 2-6.

Step 15 Enter the hosts for this zone.

The following example shows the addition of the host bethpc with an IP address of 192.168.1.5.


Figure 2-6: Add Host Dialog Box

Step 16 Click OK.

Step 17 Click Close.

Note Do not check the Generate reverse mapping records check box until you have configured the corresponding reverse zone. For instructions on configuring a reverse zone, see the "Configuring a Reverse Zone" section.

Importing From a BIND Zone File

If you have existing BIND configuration files, you can quickly create zones by importing them into Network Registrar.

Step 1 From the Server Manager window, select the DNS server, for example DNS@localhost. See Figure 2-1.

Step 2 Click the Add toolbar button to display the Add Zone dialog box. See Figure 2-2.

Step 3 In the Name field, enter the primary zone's domain name.

Step 4 Click the Primary button.

Step 5 Do one of the following:


Figure 2-7: Opening the BIND Zone File

Step 6 Click OK.

Network Registrar imports the contents of your BIND zone file, except for any comments.

Configuring a Reverse Zone

In order to have a correct DNS configuration, you must have a reverse zone for each network you are using. A reverse zone is a primary zone that allows the Internet to convert IP addresses back to host names. Reverse zones are all in the special domain, in-addr.arpa.

You can create a reverse zone manually or if you have configured a reverse zone using BIND, you can import it.

Manually Configuring a Reverse Zone

Step 1 From the Server Manager window, select the DNS server, for example DNS@localhost. See Figure 2-1.

Step 2 Click the Add toolbar button to display the Add Zone dialog box.

Step 3 Enter the reverse zone name. See Figure 2-8.

Your reverse zone's name is the inverse of your Internet network number, added to the special domain in-addr.arpa. For example, if your network number is a.b.c.0, then your inverse zone name is c.b.a.in-addr.arpa. On the other hand, if your network number is a.b.0.0, then your inverse zone name is b.a.in-addr.arpa.


Figure 2-8: Entering the Reverse Zone Name

Step 4 Click the Primary button.

Step 5 Click OK.

Step 6 From the Add Primary DNS Zone dialog box, click the SOA (Start of Authority) tab. See Figure 2-3.

Step 7 In the Contact email address field, enter the e-mail address of the administrator. Remember to use "." instead of "@."

Step 8 In the Name of primary server host field, enter the name of the primary server.

Use either the host name (ns) or the full name. If you use the full name, such as ns.example.com., remember to end the name with a period.

Step 9 In the remaining fields, enter the appropriate values for the various times or accept the defaults.

Step 10 Click the Name Servers tab. See Figure 2-4.

Step 11 Enter the authoritative servers for this zone that are registered authorities with InterNIC.

Use either the host name (ns) or the full name, ns.example.com. If you use the full name, remember to end the name with a period.

Step 12 Click Close.

Note After you have configured a reverse zone, Network Registrar automatically creates all the appropriate host address-to-name entries as you add hosts from the Add Hosts dialog box.

Importing a Reverse Zone From BIND

Step 1 From the Server Manager, select the DNS server, for example DNS@localhost. See Figure 2-1

Step 2 Click the Add toolbar button to display the Add Zone dialog box.

Step 3 In the Name field, enter the reverse zone name. See Figure 2-8.

Step 4 Click the Primary button.

Step 5 Do one of the following:

Step 6 Click OK.

Network Registrar imports the contents of your BIND zone file, except for any comments.

Note After you have configured a reverse zone, Network Registrar automatically creates all the appropriate host address-to-name entries as you add hosts from the Add Hosts dialog box.

Reloading the DNS Server

After you have configured the DNS server, you need to reload it to write the configuration information to Network Registrar's database.

Note You will see a red star on the server in the tree control if the server has never been successfully started. After the server has been started, you will only see the red star if you make a change to the server.

Step 1 From the Server Manager window, select the server you want to reload. See Figure 2-1.

Step 2 Click the Control toolbar button to display the Control dialog box.

Step 3 Click Reload. See Figure 2-9.


Figure 2-9: Control Dialog Box

Step 4 Click OK.

Network Registrar displays a dialog box that tells you whether the server has successfully reloaded and also gives you an opportunity to view the log messages. See Figure 2-10. Every time you stop, start, or reload the server you have an opportunity to view the logs.

Note These are not all the log messages, but rather just the configuration messages. To see the entire log, go to the \Registrar\Logs directory and view the name_dns_1_log file.

Figure 2-10: Server Control Results Dialog Box

Configuring Your DHCP Server

Dynamic Host Configuration Protocol (DHCP) is an industry-standard protocol for automatic assignment of IP configuration to workstations. DHCP uses a client-server model for address allocation. As administrator, you can configure one or more DHCP servers to provide IP address assignment and other TCP/IP-oriented configuration information to your workstations. DHCP frees you from having to manually assign an IP address to each client.

To configure your DHCP server, Network Registrar needs the following information:

After your DHCP server is configured, you can view your leases to monitor lease use and availability.

Note Immediately after you have installed Network Registrar, the DHCP server will be in a stopped state because it has no leases to offer. Network Registrar logs a configuration error because there are no leases configured.

Configuring the DHCP Server's Address

Network Registrar, by default, determines the IP address of the interface card on your DHCP server host. If you have several interface cards in your system, Network Registrar uses all of them. If you want to use one interface only, you need to specify the DHCP server's interface address.

Step 1 From the Server Manager window, select the DHCP server to configure. See Figure 2-1.

Step 2 Click the Show Properties toolbar button to display the DHCP Server Properties dialog box.

Step 3 Click the General tab. See Figure 2-11.


Figure 2-11: General Tab

Step 4 Click Use interface.

Step 5 In the IP address field, enter the IP address.

Step 6 In the Net mask field, enter the net mask of the server's specific interface card you want to use.

Step 7 Click OK.

Configuring a Policy

Policies enable you to group lease times and other configuration parameters that a DHCP server assigns to a client. These parameters are called DHCP options.

Policies are especially useful if you have more than one scope at your site. You can create a policy that applies to all the scopes on the current server, or create a policy for a selected scope. Policies are a convenient way of ensuring that your DHCP server supplies all the correct options for scopes and frees you from the task of specifying the information separately per scope.

Step 1 From the Server Manager window, select the DHCP server for which you want to create a policy. See Figure 2-1.

Step 2 Click the Show Properties toolbar button to display the DHCP Server Properties dialog box.

Step 3 Click the Policies tab. See Figure 2-12.


Figure 2-12: Policies Tab

Step 4 Click New to display the New Policy dialog box. See Figure 2-13.

Step 5 In the Name field, enter the policy's name.


Figure 2-13: New Policy Dialog Box

Step 6 Do one of the following:

Step 7 Click OK.

Step 8 On the Policies tab, choose whether you want the leases to be permanent, (never expire) or whether you want leases to have a duration.

If you want them to be permanent, click Leases are permanent and skip to step 11, otherwise continue to step 9.

Step 9 Set the duration of the lease, for example 7 days.

Step 10 Set the duration of the grace period, for example 4 days.

The lease grace period is the length of time that the lease is retained in the DHCP server's database after it has expired. The grace period protects a client's lease in cases where the client and server are in different time zones, the computer clocks are not synchronized, or the client was not on the network when the lease expired.

Step 11 Click Edit Options to select and configure any additional options. See Figure 2-14.

For all clients, you should configure options for routers, domain name, and domain name servers.

Note If you plan to use dynamic DNS update, you must configure a policy with these options. In addition, if you are using Microsoft networking you must configure the netbios-name server option (WINS server).

Figure 2-14: Edit Options Dialog Box

Step 12 From the Available column, select the option you want to add.

Step 13 Click Add.

Step 14 Enter the appropriate value in the Option value(s) field.

Step 15 Repeat this procedure to continue adding options.

Step 16 Click OK when you are done.

Step 17 Click Close.

Adding a Scope

A scope contains a set of IP addresses for part of or an entire subnet, and an associated policy that tells DHCP how to operate on these addresses. You must define at least one scope for each subnet on which you want a DHCP server to supply IP addresses to DHCP clients.

Note You can have more than one scope per subnet, and you can combine secondary subnets as well. For more information, see the Network Registrar GUI User's Guide or the online help.

Step 1 From the Server Manager window, select the DHCP server to which you want to add a scope. See Figure 2-1.

Step 2 Click the Add toolbar button to display the Add Scope dialog box. See Figure 2-15.

Step 3 In the Name field, enter the name of the scope.


Figure 2-15: Add Scope Dialog Box

Step 4 In the Policy field, do one of the following:

Step 5 In the Network number field, enter the server's network number, for example, your Internet Class B or Class C address.

Step 6 In the Subnet mask field, enter the subnet mask.

Step 7 In the Start/End Address columns, specify the scope address range by typing a series of single addresses and/or address ranges.

Step 8 Click OK.

Reloading the DHCP Server

After you have configured the DHCP server, you need to reload it to write the configuration information to Network Registrar's database.

Note You will see a red star on the server in the tree control if the server has never been successfully started. After the server has been started, you'll only see the red star if you make a change to the server.

Step 1 From the Server Manager window, select the server you want to reload. See Figure 2-1.

Step 2 Click the Control toolbar button to display the Control dialog box. See Figure 2-16.

Step 3 Click Reload.


Figure 2-16: Control Dialog Box

Step 4 Click OK.

Network Registrar displays a dialog box that tells you whether the server has successfully reloaded, and gives you a chance to view the log messages. See Figure 2-17. Every time you stop, start, or reload the server you have an opportunity to view the logs.

Note These are not all the log messages, but rather just the configuration messages. To see the entire log, go to the \Registrar\Logs directory and view the name_dhcp_1_log file.

Figure 2-17: Server Control Results Dialog Box

Viewing Leases

After you have established a scope, you can monitor lease activity from the DHCP Scope Leases tab.

Step 1 From the Server Manager window, select the scope whose leases you want to view. See Figure 2-1.

Step 2 Click the Show Properties toolbar to display the Scope dialog box.

Step 3 Click the Leases tab. See Figure 2-18.


Figure 2-18: Leases Tab

This dialog box displays the following information:
Note If you have a RAS (Remote Access Server) on one of your LANs, you might see it using some of your DHCP leases. RAS servers continually broadcast DHCP requests for the two or three addresses they can use.

Making Reservations

If you would like to ensure that a client always gets the same lease, you need to reserve a lease. You reserve a lease by pairing an IP address with the host's MAC address. You can choose any valid IP address that is within your network number. The IP address does not have to be one that is listed in the scope's range of addresses. In fact, you can use the scope's range of IP numbers for dynamic leases, and use other addresses for reserved leases.

Note Even though a reserved IP address may not be listed in the scope's range of IP addresses, it is still part of the scope, and the policy attached to the scope applies to it.

Network Registrar provides two ways to make reservations. If you want to reserve several leases, use the Reservations tab dialog box. If you want to reserve a lease that is currently held or available, you can do so from the Leases tab dialog box.

Reserving Several Leases

Step 1 From the Server Manager window, select the DHCP scope that has the appropriate policy for your lease reservation. See Figure 2-1.

Step 2 Click the Show Properties toolbar button to display the Scope Properties dialog box.

Step 3 Click the Reservations tab. See Figure 2-19.


Figure 2-19: Reservations Tab

Step 4 Click Add.

Step 5 In the Add Reservation dialog box, enter the lease address and MAC address. See Figure 2-20.


Figure 2-20: Add Reservation Dialog Box

Step 6 Click Apply to continue adding reservations.

Step 7 When you are finished, click OK.

Reserving Individual Leases

Step 1 From the Server Manager window, select the DHCP scope that contains the address or addresses you want to reserve. See Figure 2-1.

Step 2 Click the Show Properties toolbar button to display the Scope Properties dialog box.

Step 3 Click the Leases tab. See Figure 2-18.

Step 4 Select the address of the lease you want to reserve.

Step 5 Click Lease properties. See Figure 2-21.


Figure 2-21: Lease Properties Dialog Box

Step 6 Select the Reserve lease check box and do one of the following:

Step 7 Click OK.

Configuring Dynamic DNS Update

Dynamic DNS update is the integration of DNS and DHCP. The two protocols are complementary: DHCP centralizes and automates the allocation of IP addresses, and dynamic DNS update automatically records the association between assigned addresses and host names.

When you use DHCP and dynamic DNS update, a host is automatically configured for network access whenever it attaches to the IP network. The host can be located and accessed using its permanent, unique DNS host name. Mobile hosts, for example, can therefore move freely around on a network without end-user or administrator intervention.

To configure dynamic DNS update, you need to configure both a DHCP scope and a primary DNS zone, and supply host names. You can request that Network Registrar generate host names, or you can supply them.

Note You can only update a primary DNS server that supports dynamic DNS update.

Configuring Dynamic DNS Update for the Scope

Step 1 From the Server Manager window, select the DHCP scope you want to associate with dynamic DNS update. See Figure 2-1.

Step 2 Click the Show Properties toolbar button.

Step 3 In the DNS tab of the Scope Properties dialog box, select the Perform dynamic DNS updates check box. See Figure 2-22.


Figure 2-22: DNS Tab

Step 4 In the DNS zone name field, enter the DNS zone name.

Step 5 In the DNS server IP address field, enter the DNS Server's IP address.

Step 6 In the DNS reverse zone name field, enter the DNS reverse zone name.

Step 7 If you want Network Registrar to create hosts names for hosts that do not supply names, select the Create host names field for hosts that do not supply one check box. If you select this box, Network Registrar will create a unique host name based on the host name prefix.

Step 8 If you want Network Registrar to use a specific host name prefix, enter one in the Create host name starting with field.

Step 9 Select whether to update DNS before or after providing a lease. The default is After responding to client.

Caution Do not choose updating "Before responding to client" if you have Windows 95 clients, because updating DNS before responding to a lease can cause delays, which then cause problems with Windows 95 DHCP clients.

Step 10 Click OK.

Configuring the Corresponding DNS Server

Step 1 From the Server Manager window, select the DNS zone that you want to configure for dynamic DNS update. See Figure 2-23.


Figure 2-23: Server Manager Window

Step 2 Click the Show Properties toolbar button to display the Zone Properties dialog box.

Step 3 Click the DHCP tab. See Figure 2-24.


Figure 2-24: DHCP Tab

Step 4 Select the Enable dynamic DHCP updates check box.

Step 5 In the Accept updates from these addresses only field, specify the address of the DHCP server from which DNS allows updates.

If you do not list a DHCP server, dynamic updates will not occur.

Step 6 Repeat this procedure for both the zones; for example the primary zone example.com and the reverse zone 1.168.192.in-addr.arpa.

Note If the DNS zone and the DHCP scope are on the same machine, be sure to include the loopback address 127.0.0.1 in the DNS server's list of addresses from which it accepts updates to ensure that dynamic updates occur in both the primary and reverse zones.

Reloading the Servers

After you have configured the DNS and DHCP servers, you need to reload them to write the configuration information to Network Registrar's database.

Step 1 From the Server Manager window, select the first server you want to reload, for example the DNS server. See Figure 2-23.

Step 2 Click the Control toolbar button to display the Control dialog box. See Figure 2-25.

Step 3 Click Reload.


Figure 2-25: Control Dialog Box

Step 4 Click OK.

Step 5 Repeat for the second server, for example the DHCP server.


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Posted: Thu Jul 13 11:19:26 PDT 2000
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