Table of Contents

Administering Clusters

Adding a Cluster
Removing a Cluster
Connecting to a Cluster
Disconnecting From a Cluster
Viewing a Cluster's State

Handling Administration

Adding an Administrator
Creating a Password Without Displaying It
Changing the Administrator's Password
Listing Network Administrators
Exiting Network Registrar

Controlling Servers

Starting the Servers
Stopping the Servers
Reloading the Servers

Using Event Logging for the Servers

Logging Format
Log Files

Debugging the Servers
Monitoring and Reporting the Server's Status

Adding Servers to the Server Status Monitor
Removing Servers from the Server Status Monitor
Displaying the Server's Health
Displaying Server Statistics
Displaying IP Address Usage
Displaying Related Servers
Displaying Leases

Backing Up the Database

Configuring Servers for Backup

Using the Backup Command-Line Utility (mcdshadow)
Checking Database Integrity
Recovering Data
Mcdshadow Files Created During Backup

Administering Network Registrar

This chapter explains how to administer and control your servers' operations through Network Registrar's graphical user interface (GUI), ntwkreg, and the command line interface (CLI), nrcmd.

Table 3-1 lists the major Network Registrar server administration tasks and the sections where you can find procedural information about how to accomplish those tasks.

For more basic information about the Network Registrar's user interfaces, see the "Network Registrar User Interfaces" chapter in this guide.

Administering Clusters

A cluster is a group of DNS or DHCP servers that share the same Network Registrar database. Adding a cluster tells Network Registrar about the existence of a cluster. To configure or administer the cluster, you must also connect to it.

Adding a Cluster

Each cluster requires a username-password combination, which Network Registrar uses to control access to each cluster.

Step 1 From the Admin menu, select Clusters (Figure 2-2).

Step 2 In the Clusters dialog box, click Add Cluster. The Add Cluster dialog box appears (Figure 3-1).

Removing a Cluster

When you remove a cluster, the user interface no longer knows about the cluster and its name does not appear in the Server Manager.

Step 1 From the Admin menu, select Clusters (Figure 2-2).

Step 2 In the Clusters dialog box, select the cluster you want to remove.

Step 3 Click Remove.

Step 4 Click Yes in the Network Registrar dialog box.

Step 5 Click Close to exit the Clusters dialog box.

Connecting to a Cluster

After you have added a cluster to Network Registrar, you must connect before you can configure or administer the cluster.

Step 1 From the Admin menu, select Clusters (Figure 2-2).

Step 2 In the Clusters dialog box, select the cluster you want to connect.

Step 3 Click Connect.

Step 4 Click Close.

Using the CLI:

Use the nrcmd -C switch to connect to a cluster. For example, to connect to the mycluster cluster, type the following from a command line prompt:

C:\Program Files\Network Registrar> nrcmd -C mycluster

Disconnecting From a Cluster

When you disconnect from a cluster it can no longer be configured or administered from that workstation. Another user can then administer the connection.

Using the GUI:

Step 1 From the Admin menu, select Clusters (Figure 2-2).

Step 2 In the Clusters dialog box, select the cluster you want to disconnect.

Step 3 Click Disconnect.

Step 4 Click Close to exit the Clusters dialog box.

Using the CLI:

Use the exit command at the nrcmd prompt to disconnect from a cluster.

nrcmd> exit

Viewing a Cluster's State

To see whether a cluster is connected or not, you can view its state.

Using the GUI:

Step 1 From the Admin menu, select Clusters (Figure 2-2).

Network Registrar displays the cluster's state.

Step 2 Click Close.

Using the CLI:

The CLI is always connected to one cluster if it is successfully invoked. Use the getHealth command to return a number that indicates the condition of the server. For example, 10 represents normal operation and 1 indicates that the server has stopped.

nrcmd> server DHCP getHealth

Handling Administration

From the Admin command level (GUI) or using the CLI admin command, you can add administrators, change passwords, and configure administrators for the cluster.

Adding an Administrator

Using the GUI:

Step 1 From the Admin menu, select Add Administrator (Figure 2-2).

Step 2 Enter the administrator's username.

You can choose any string for the administrator's name.

Step 3 Enter the administrator's password.

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Note Network Registrar uses the password to authenticate the names. If you create an administrator without a password, Network Registrar cannot authenticate the name and thus will deny that user access to the cluster.

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Step 4 Enter the password a second time.

Step 5 Select the clusters the administrator can access.

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Note You can only select clusters that have been added to the cluster list through the Add Cluster command. However, you do not have to be connected.

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Step 6 Click Add.

Using the CLI:

Use the admin create command to create an administrator and associated password. For example, to create the administrator bob with the password of xyz, type:

nrcmd> admin bob create password=xyz

Creating a Password Without Displaying It

Using the CLI:

If you want to enter a password and not have Network Registrar display the password on your screen, create an administrator and do not supply a password. Then use the enterPassword command to enter a password and prevent Network Registrar from echoing it on the screen. Network Registrar prompts you to verify the password before it accepts it.

nrcmd> admin bob enterPassword

Changing the Administrator's Password

Using the GUI:

Step 1 From the Admin menu, select Change Administrator Password (Figure 2-2).

Step 2 Enter the administrator's username.

Step 3 Enter the administrator's current password.

Step 4 Enter the administrator's new password.

Step 5 Enter the new password a second time.

Step 6 Select the cluster the administrator can access.

Step 7 Click OK.

Using the CLI:

Use the admin set command to change an existing password. For example, to change bob's password to abc, type:

nrcmd> admin bob set password=abc
 

Caution It is possible to lock an administrator out of Network Registrar by logging in as that administrator and setting the password for another administrator without confirming the previous password. This procedure effectively prevents the first administrator from logging in.

Listing Network Administrators

Use the admin list command to list all administrator in Network Regisrar.

nrcmd> admin list

Exiting Network Registrar

Exiting the Network Registrar user interface does not affect your network servers' or your hosts' ability to request leases or access the Internet.

Using the GUI:

Step 1 From the Admin menu, select Exit (Figure 2-2).

If you have not saved configuration changes, Network Registrar prompts you to save changes.

Using the CLI:

To exit Network Registrar's CLI, use the exit command. Network Registrar writes all your unsaved changes to the database. If Network Registrar is unable to save your changes, it displays the same error code as if you had used the save command.

nrcmd> exit

Controlling Servers

Network Registrar administration for controlling includes:

Starting the Servers

Using the GUI:

Step 1 From the Server Manager window (Figure 2-2), select the server you want to start.

Step 2 From the Servers menu, select Start.

You will see a red star on the server in the tree control if you make a change to the server.

Step 3 Click OK.

Using the CLI:

Use the server start command to start the specified server. For example, to start Network Registrar's DNS server, type:

nrcmd> server DNS start

Stopping the Servers

Using the GUI:

Step 1 From the Server Manager window (Figure 2-2), select the server you want to stop.

Step 2 From the Servers menu, select Stop.

Step 3 Click OK.

Using the CLI:

Use the server stop command to stop the specified server. For example, to stop Network Registrar's DHCP server, type:

nrcmd> server DHCP stop

Reloading the Servers

When you reload the server, Network Registrar performs several steps: it stop the server you have selected, updates the database with the new configuration information, and restarts the server. Only after you issue the reload command does the server use your changes to the configuration.

Using the GUI:

Step 1 From the Server Manager window (Figure 2-3), select the server you want to reload.

Step 2 From the Servers menu, select Reload.

Step 3 Click OK.

Using the CLI:

Use the server reload command to reload the specified server. For example, to reload Network Registrar's DHCP server, type:

nrcmd> server DHCP reload
 

Network Registrar stops the server you have selected, updates the database with the new configuration information, and restarts the server.

Using Event Logging for the Servers

When you start Network Registrar, it automatically starts logging system activity. Network Registrar maintains all the logs in the Program Files\Network Registrar\logs (Windows NT) or /var/nwreg2/logs (UNIX) directory. If you would like to view the contents of these logs while the Network Registrar servers are running, issue the command tail -f (Solaris), or view the files through the Web browser (Windows NT).

Caution o avoid filling up the Windows NT event log, change the Log Settings to Overwrite Events as Needed. If you do not make this change, you might fill up your disk with log messages and thus prevent Network Registrar from running.

This section describes the types of logs that Network Registrar keeps and explains how to set and view the debug logging options.

Logging Format

The format for the log entries are the following categories:

• Activity---Messages about the activity of your servers.

• Info---Logs standard operations of the servers, such as starting up and shutting down.

• Warning---Logs events that warn users of events, such as invalid packets, user miscommunication, or an error in a script while processing a request.

• Error---Logs events that prevented the server from operating properly, such as out of memory or unable to acquire resources (sockets, logs, backing store or configuration databases) or errors in configuration.

Log Files

Table 3-2 shows all the Network Registrar log files.

Debugging the Servers

You can set the debug settings for the Network Registrar DNS and the DHCP servers.

You can use Mlog to add the debug messages to the existing logs.

The Debug settings button lets you collect debug information about the DNS server. You should only need to set debug settings if you have been instructed by Technical Support.

Step 1 From the Server Manager (Figure 2-3), select the server for which you want to set debug options.

Step 2 Click the Show Properties toolbar button.

Step 3 Click the Advanced tab on the Show Properties dialog box (Figure 2-7).

Step 4 Click Debug settings.

Step 5 From the Debug Settings dialog box, click Enable Debug.

Step 6 Type in the category as supplied by Technical Support.

Step 7 Check MLOG, which sends the output to the Network Registrar's files.

Step 8 Click OK.

Using the CLI:

You can use the server setDebug and server unsetDebug commands to set or unset the debugging level.

nrcmd> server DNS setDebug D=5
 

Monitoring and Reporting the Server's Status

You can monitor the state of your Network Registrar servers by displaying or reporting aspects of a specified server's health. The following items can decrement the health of the servers so you should monitor their status periodically:

Adding Servers to the Server Status Monitor

Perform these steps to view server status.

Using the GUI:

The Server Status Monitor window (Figure 3-2) is a window in which you can place server icons to monitor their state. The icons change to reflect the server's current state. The traffic lights indicate the state of the server: started is green and stopped is red.

The bar to the right of the traffic light shows the health of the server, that is, it indicates how well the server is running. The health is a combination of servers' resources and network balance

Step 1 From the Server Manager window (Figure 2-3), select the server you want to add.

Step 2 From the Servers menu, select Add to Status Monitor, or, from Windows 95 or Windows NT, drag the server icon to the Server Status Monitor window (Figure 3-2).

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Note You can add as many servers as you want to the Server Status Monitor (Figure 3-2). They can be from any of the clusters to which you have connected.

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Removing Servers from the Server Status Monitor

Perform these steps to remove servers from the Server Status Monitor.

Using the GUI:

Step 1 In the Server Status Monitor window (Figure 3-2), select the server you want to remove.

Step 2 Use the right mouse button (right-click) to select Remove.

Displaying the Server's Health

You can display the health of a server, that is, whether it is running or stopped.

Using the CLI:

Use the server getHealth command to display the specified server's health. For example, to display Network Registrar's DHCP server's health, type:

nrcmd> server DHCP getHealth

Displaying Server Statistics

Perform these steps to display server statistics.

Using the GUI:

Step 1 From the Server Manager window (Figure 2-3), select the server whose statistics you want to view.

Step 2 From the Servers menu, select Show Statistics.

Network Registrar displays the Statistics window.

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Note You can sort the statistics by Name or by Value by clicking the corresponding column. To see updated statistics, click Refresh.

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Using the CLI:

Use the server getStats command to display the specified server's statistics. For example, to display Network Registrar's DHCP server's statistics, type:

nrcmd> server DHCP getStats

For information about how to run the Server status report, see "Running the Server Status Report" section.

Displaying IP Address Usage

Perform these steps to display IP address usage.

Using the CLI:

Use the report file outputfile command to display the IP address usage for specified servers. For example, to display Network Registrar's DHCP server's address usage, type:

nrcmd> report file myreportfile

For information about how to run the Address usage report, see "Running the Address Usage Report" section.

Displaying Related Servers

Network Registrar displays a report that contains the following information:

• Type---Main or backup DHCP server

• Server name---The DNS name of the server

• IP address---The server's IP address in dotted octet format

• Requests---The number of outstanding requests for packets or two dashes if not applicable

• Communication status---Whether the servers can communicate or if communication has been interrupted (OK or INTERRUPTED)

• Cluster state---The failover state of this DHCP server

• Partner state---The failover state of partner server

Step 1 From the Server Manager window (Figure 2-3), select the DHCP server.

Step 2 From the Servers menu, select Show related servers.

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Note This command is only available if you have configured DHCP failover.

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Network Registrar refreshes this document window every 10 seconds. If you want more current information, click Refresh.

Using the CLI:

Use the server getRelatedServers command to display the connection status between the main and backup DHCP server. For example, to display Network Registrar's DHCP servers, type:

nrcmd> server DHCP getRelatedServers

For information about how to run the Related servers report, see "Running the Related Servers Report" section.

Displaying Leases

After you have established a scope, you can monitor lease activity and view lease attributes using either the Leases tab in the GUI or the CLI lease list command.

Using the GUI:

Step 1 From the Server Manager window (Figure 2-3), select the scope whose leases you want to view.

Step 2 From the DHCP Scope properties dialog box, click the Leases tab.

Step 3 Select the lease that you want to view.

Step 4 Click Lease Properties. The properties of the lease you selected displays.

Using the CLI:

Use the lease list command from the DOS prompt to view the properties of a particular lease. For example:

For information about how to run the Lease status report, see "Running the Lease Status Report" section.

Backing Up the Database

To ensure a consistent snapshot of the Network Registrar database, Network Registrar provides a shadow backup facility. Because the Network Registrar database (called MCD) does a variety of memory caching and may be active at any time, you cannot rely on doing system backups to protect the data in the database. At the time you run a system backup, there may be Network Registrar operations in progress that cause the data copied to the system backup tape to be inconsistent, and unusable as a replacement database.

You can also use Network Registrar's shadow backup facility. Once a day, at a configurable time, Network Registrar suspends all activity to the database, and takes a snapshot of the critical files. This snapshot is guaranteed to be a consistent view of the database, and it will be preserved correctly on a system backup tape. This backup is only a single generation backup. To maintain multiple backup versions, implement an archiving strategy.

Caution If you are using Windows NT, make sure you backup the files only in the db.bak directory. Otherwise, you might cause your server to crash.

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Note Network Registrar backs up the DNS data even when the shadow backup is run on a secondary server.

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Configuring Servers for Backup

The only configuration for this facility is through a single entry in the system Registry.

HKEY_LOCAL_MACHINE/SOFTWARE/American Internet/NetworkRegistrar/2.0/DBShadowTime

Using the Backup Command-Line Utility (mcdshadow)

In addition to being available at a scheduled time of day, you can also force a shadow backup manually by using the mcdshadow utility located in the \Program Files\Network Registrar\bin directory for Windows NT or the /opt/nwreg2/usrbin directory for UNIX. There are no command-line arguments. Type mcdshadow to cause Network Registrar to perform the shadow backup.

Checking Database Integrity

Step 1 Stop all Network Registrar servers.

Step 2 Change the directory to \Program Files\Network Registrar\data\db (Windows NT) or /var/nwreg2/data/db (UNIX).

Step 3 As a safety check, type the command ..\..\bin\dbcheck mcddb (Windows NT) or /opt/nwreg2/dbcheck -a mcddb (UNIX) to verify the integrity of the database.

Recovering Data

Use the shadow backup to recover data, either because a system crash corrupted the regular working database or because the disk on which it resides is corrupted.

Step 1 Stop the AIC Server Agent within UNIX by typing the command aicservagt stop (UNIX) or within Windows NT, select Start/Settings/Control Panel/Service, highlight AIC Server Agent, and click stop.

Caution If you do not stop the AIC Server Agent, you will get errors.

Step 2 Make sure that the following three files are in \Program Files\Network Registrar\data\db.bak (Windows NT) or /var/nwreg2/data/db (UNIX).

The files are mcddb.d01, mcddb.d02, and mcddb.d03.

Step 3 Copy them into \Program Files\Network Registrar\data\db (Windows NT) or /var/nwreg2/data/db (UNIX). Do not move them because you may need them again.

Step 4 Change the directory to \Program Files\Network Registrar\data\db (Windows NT) or /var/nwreg2/data/db (UNIX).

Step 5 Type the following command to rebuild the key files by typing the command ..\..\bin\keybuild mcddb (Windows NT) or /opt/nwreg2/keybuild mcddb (UNIX).

Step 6 As a safety check, type the command ..\..\bin\dbcheck mcddb (Windows NT) or /opt/nwreg2/dbcheck mcddb (UNIX) to verify the integrity of the database.

Mcdshadow Files Created During Backup

The mcdshadow command uses the files listed in Table 3-3.

Table 3-3: Mcdshadow Files

File	Description
mcddb.dbd	Template file that describes the low-level data schema for the Raima runtime library.
mcddb.k01-k03	Key files that contain the data that is redundant with the data files. Network Registrar does not back up these files because they can be completely rebuilt with the keybuild command.
mcddb.d01-d03	Data files that contain the backup.
mcdConfig.txt	Text file from which Network Registrar configures the initial at-install-time database.
mcdschema.txt	Text file that contains a version number denoting the level of the schema contained in the dbd file. Network Registrar will not attempt to open the database unless the number in this file matches a constant that is hard-coded in the libraries. If the result of the mcdshadow (which it just copies of the data files) is divorced from its original mcdschema.txt, you will not be able to run Network Registrar.
vista.taf, tcf, tjf	Working files used by the Raima runtime to ensure transactional integrity.

Posted: Thu Nov 18 13:35:24 PST 1999
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