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You can use Network Registrar's client or client-class facility to provide differentiated services to users accessing a common network. You can group your user community based on administrative criteria, and then ensure that each group of users receives the appropriate class of service when they access the network.
If you do not enable client-class processing, the Network Registrar DHCP server provides client leases based solely on their location in the network.
lists the client-class configuration topics and their associated sections to go to for more information.
| If you want to... | Go to this section... |
|---|---|
Know more about why you would configure client-classes for Network Registrar servers | |
Enable client-class processing on a DHCP server | |
Add, list, or delete scope selection tags | |
Add, edit, or remove client-classes | |
Add clients that will inherit properties from the client-class they are associated with | |
List a client or all clients in a client-class and their associated properties | |
Edit client scope selection criteria | |
Edit a client's client-class properties | |
Remove a client from a client-class | |
Move a client to another subnet |
For more information about how DHCP handles client-class processing, see the Network Registrar Concepts Guide.
Although Network Registrar's client-class facility can be used to control any configuration parameter, the most common uses are for:
You can enable or disable client-class processing for the DHCP server and apply a set of properties to groups of clients. Enabling client-class processing causes the DHCP server to assign the client to an IP address from a matching scope. For every DHCP packet the server receives, it examines the client and the client-class information, and determines if this client has any stored information. If it does, the server acts on the information. If not, the processing continues just as if it were not enabled.
Follow these steps, as described in the following sections, to configure client-class:
Step 1 Enable client-class processing for the DHCP server.
Step 2 Define the scope selection tags for the DHCP server.
Step 3 Apply selection tags to specific scopes.
Step 4 Create client-classes that include or exclude those tags.
Step 5 Assign clients to these classes.
Step 1 From the Server Manager window, select the DHCP server for which you want to enable client-class processing.
Step 2 From the Show Properties toolbar button, click the Scope Selection Tags Tab (Figure 9-1).
Step 3 Click the Enable client-class processing check box, to enable client processing.
Step 4 Click OK.
Use the dhcp client-class command to enable client-class processing.
Network Registrar lets you add up to 30 scope selection tags. When the DHCP server configures itself, it checks the number of scope selection tags defined for any network. A network in this context is the aggregation of all of the scopes that are related to a particular subnet. This includes all of the scopes that belong together (because they share a common network number and subnet mask) and all of the scopes that are related to one of these through the use of the primary scope reference. Thus, within all of the scopes that make up a network, there can be no more than 30 scope selection tags.
When the DHCP server reads a client entry (from the local database or from LDAP), the server checks its scope selection inclusion and exclusion criteria against the scope selection tags defined for the scopes on this network. If the client entry references tags that are not present in any scope in the network, then how the server handles the tags depends on whether the reference is to included or excluded tags. If the reference is for excluded tags, then the tag will have no effect. If the reference is for included tags, then the server determines that there is no acceptable scope on that network for this client.
Step 2 From the Show Properties toolbar button, click the Scope Selection Tags Tab (Figure 9-1).
The Scope Selection Tags tab allows you to enable or disable client-class processing for the DHCP server, display the list of defined scope selection tags, and create new tags.
Step 3 Enter a name in the scope selection name field.
Step 4 Click Add.
When you add new selection tags, Network Registrar displays them in the list of selection tags field. You can only add selection tags, you cannot delete them from the GUI. If you change your mind before you click OK, click Cancel to rename any selection tag you have just typed. After you click OK, the newly added selection tags become confirmed.
Step 5 Click OK.
Use the scope-selection-tag create command to create a selection tag.
For example, to create the scope selection tag internal, type:
nrcmd> scope-selection-tag internal create
To debug selection tags you can use the dhcp log-settings command, particularly client-criteria-processing and unknown-criteria. For more information, about the dhcp log-settings command, see the Network Registrar CLI Reference Guide.
To delete scope selection tags, use the nrcmd program scope-selection-tag command. For more information about the scope-selection-tag command, see the Network Registrar CLI Reference Guide.
Use the scope-selection-tag delete command to delete a selection tag. For example, to delete the selection tag internal, type:
nrcmd> scope-selection-tag internal delete
Step 1 From the Server Manager window, select the DHCP server for which you want to specify scope selection tags.
Step 2 From the Show Properties toolbar button, click the Scope Selection Tags Tab (Figure 9-1).
Step 3 The list of scope selection tags for the DHCP server is displayed.
Use the scope-selection-tag list command to list selection tags.
nrcmd> scope-selection-tag list
You can display the properties of a client-class that are created. You can then add, edit, or delete client-classes.
Step 1 From the Server Manager window (Figure 2-3), select the DHCP server for which you want to display a client-class property.
Step 2 Click the Show Properties toolbar button.
Step 3 Click the Client-Classes tab (Figure 9-2) to display the client-class name, the domain name, the policy name, the scope selection tags to include (Includes), and the scope selection tags to exclude (Excludes) for each of the client-classes that you have defined.
Use the client-class list command to display client classes.
nrcmd> client-class list
You can create client-classes and apply a set of properties to groups of clients.
Step 1 From the Server Manager window (Figure 2-3), select the DHCP server for which you want to create a client-class.
Step 2 Click the Show Properties toolbar button.
Step 3 In the DHCP Server Properties dialog box, click the Client-Classes tab (Figure 9-2).
Step 4 In the Client-Classes tab, click Add (Figure 9-3).
Step 5 In the Add Client-Class dialog box, enter or select the following:
Step 6 Click OK to finish or Apply to continue adding client-classes.
nrcmd> client-class internal-users create
You can specify which scope selection tags to include or exclude in a client-class.
Network Registrar handles inclusion and exclusion for the applicable subnet in the following manner:
For example, assume three scopes, A, B, and C, with the following attributes: A/red, B/blue, C/blue,green. If a client-class specified inclusion of red, then the client would get an address from scope A. If a client-class specified inclusion of blue, then the client would get an address from either scope B or C. If a client-class specified inclusion of blue and exclusion of green, then the client would get an address from scope B.
Step 1 From the Server Manager, From the Server Manager window (Figure 2-3), select the DHCP server for the client-class you want to edit.
Step 2 Click the Show Properties toolbar button.
Step 3 Click the Client-Classes tab (Figure 9-2).
Step 4 From the Add Client-Class dialog box, click Edit Criteria.
Step 5 In the Edit Scope Selection Criteria dialog (Figure 9-4), select the check boxes for the scope selection tags that you want included and excluded in this client-class.
Step 6 Click OK.
Use the client-class set command to set the inclusion scope selection criteria. For example, to include the scope selection tag internal in the client-class internal-users, type:
nrcmd> client-class internal-users set selection-criteria=internal
Use the client-class set command to set the exclusion scope selection criteria. For example, to exclude the previously created scope selection tag external in the client-class internal-users, type:
nrcmd> client-class internal-users set selection-criteria-excluded=external
Before removing a client-class, determine if there are any clients who reference that client-class. If there are, they will not get the service specified in the client-class. They will get the default service instead. A warning will appear stating that the client is configured with a client-class that does not exist.
Step 1 From the Server Manager window (Figure 2-3), select the DHCP server from which you want to remove a client-class.
Step 2 Click the Show Properties toolbar button.
Step 3 In the DHCP Server Properties dialog box, click the Client-Classes tab (Figure 9-2).
Step 4 In the Client-Classes tab, select the client-class you want to remove.
Step 5 Click Remove.
Use the client-class delete command to remove a client-class. For example, to delete the client-class internal-users, type:
nrcmd> client-class internal-users delete
To debug client problems, you can use the nrcmd dhcp command log-settings properties, particularly client-detail. For more information, see the Network Registrar CLI Reference Guide.
Editing a client-class enables you to change options such as selection criteria and policy name.
Step 1 From the Server Manager window (Figure 2-3), select the DHCP server on which you want to edit a client-class.
Step 2 Click the Show Properties toolbar button.
Step 3 In the DHCP Server Properties dialog box, click the Client-Classes tab (Figure 9-2).
Step 4 In the Client-Classes tab, select the client-class you want to edit.
Step 5 Click Edit.
Step 6 In the Edit Client-Class dialog box (Figure 9-5), click the field you want to edit.
Step 7 Type or select the new field information.
Step 8 Click OK.
Use the client-class set command to edit the properties of the clients. For example, to change the policy that the client-class uses, type:
nrcmd> client-class internal-users set policy-name=long
You can display the properties of a single client.
The Clients tab (Figure 9-6) displays the MAC address, the client-class, the host name, the domain name, the policy, and the action properties for all the clients in the cluster.
Use the lease list command to display the MAC address, the client-class, the host name, the domain name, the policy, and the action properties for all the clients in the cluster.
nrcmd> lease list
A client inherits the properties from its client-class, which you may choose to override or supplement by specifying different ones for the client.
Step 1 From the Server Manager window (Figure 2-3), select the DHCP server for which you want to create a class.
Step 2 Click the Show Properties toolbar button.
Step 3 In the DHCP Server Properties dialog box, click the Clients tab (Figure 9-6).
Step 4 In the Clients tab, click Add. The Add Client dialog box appears (Figure 9-7).
Step 5 In the Add Client dialog box, enter or select the following:
Step 6 Click OK to finish or Apply to continue adding clients.
A client inherits the properties from its client-class, which you may choose to override or supplement by specifying different ones for the client.
Step 1 Use the client create command to create a client.
Specify the client by MAC address.
nrcmd> client 1,6,06:44:40:26:f5:0f create
Step 2 Use the client set command to set the following client properties:
To apply the authenticate-until property (with a value of forever) to the client-class internal-users, type:
nrcmd> client interval-users set authenticate-until forever
For example, to set the policy, type:
nrcmd> client 1,6,06:44:40:26:F5:0F set policy-name=CompanyB
Step 1 From the Server Manager window (Figure 2-3), select the DHCP server for which you want to display a client's properties.
Step 2 Click the Show Properties toolbar button.
Step 3 In the DHCP Server Properties dialog box, click the Clients tab (Figure 9-6).
The list of clients and their associated properties displays.
Use the client show command to display properties of a specific client. For example, to display the client 1,6:03:03:03:03:03:03, type:
nrcmd> client 1,6,06:44:40:26:f5:0f show
Step 1 From the Server Manager window (Figure 2-3), select the DHCP server for which you want to display a client's properties.
Step 2 Click the Show Properties toolbar button.
Step 3 In the DHCP Server Properties dialog box, click the Clients tab (Figure 9-6).
The list of clients and their associated properties displays.
Use the client list command to display properties for all the clients.
nrcmd> client list
Step 1 From the Server Manager window (Figure 2-3), select the DHCP server on which you want to edit a client.
Step 2 Click the Show Properties toolbar button.
Step 3 In the DHCP Server Properties dialog box, click the Clients tab (Figure 9-6).
Step 4 From the Add Client dialog box, click Edit Criteria.
Step 5 From the Edit Scope Selection Criteria dialog box, select the check boxes for the scope selection tags that you want included and excluded for this client (Figure 9-4).
Step 6 Click OK.
Use the client set command to set new scope selection criteria. The tags must already have been created with the scope-selection-tag command.
nrcmd> client 1,6,02:02:02:02:02:02 set selection-criteria=laptop
Step 1 From the Server Manager window (Figure 2-3), select the DHCP server on which you want to edit a client.
Step 2 Click the Show Properties toolbar button.
Step 3 In the DHCP Server Properties dialog box, click the Clients tab (Figure 9-6).
Step 4 In the Clients tab, select the client you want to edit.
Step 5 Click Edit.
Step 6 In the Edit Clients dialog box, click the field you want to edit.
Step 7 Type or select the new field information.
Step 8 Click OK.
Use the client set command to change the value of a property. For example, to change the client's client-class-name, type:
nrcmd> client 1,6:03:03:03:03:03:03 set client-class-name=external-users
Step 1 From the Server Manager window (Figure 2-3), select the DHCP server from which you want to remove a client.
Step 2 Click the Show Properties toolbar button.
Step 3 In the DHCP Server Properties dialog box, click the Clients tab (Figure 9-6).
Step 4 In the Clients tab, select the client you want to remove.
Step 5 Click Remove.
Use the client delete command to delete a client.
nrcmd> client 1,6:03:03:03:03:03:03 delete
If you move a DHCP client machine from one subnet to another, you need to either reboot the machine when it arrives on the new subnet, or explicitly release and re-acquire a lease using winipcfg.exe (for Windows 95), or ipconfig /release and ipconfig /renew (for Windows NT). You must do this because until the lease expires on the machine that was moved, it will be using an IP address that is incorrect for the network on which it is placed. You are most likely to see this situation when you move laptop computers.
Posted: Thu Feb 3 11:03:44 PST 2000
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