A name server (NS) group is a collection of one or more DNS servers. Grouping a commonly used set of DNS servers together simplifies zone creation by enabling you to specify a single NS group instead of specifying multiple name servers individually.
You can configure the following types of name server groups:

• Authoritative name server group

• Delegation name server group 

• Forwarding member name server group 

• Stub member name server group 

• Forward/Stub server name server group 

Using Authoritative Name Server Groups

An authoritative name server group is a collection of one or more primary DNS servers and secondary DNS servers. After you create an authoritative NS group, you can then assign it to serve authoritative forward-mapping and reverse-mapping zones. When you assign an authoritative NS group to an authoritative zone, Grid Manager automatically generates an NS record, a glue A or AAAA record, and a PTR record for each name server available in the NS group. But if the zone is disabled, Grid Manager does not generate these records.
Grid Manager generates authoritative A, AAAA, and PTR records when:

• A Grid member is added to a Grid, whose host name belongs to the name space of the authoritative zone and vice versa.

• An external name server is assigned to a zone, whose host name belongs to the name space of the authoritative zone.

The performance of the following functions significantly improve when you assign an NS group to a zone instead of specifying multiple name servers individually:

• Starting and Stopping the DNS service.

• Reparenting the zones after removing or restoring a zone.

• Modifying the zone data.

Adding Authoritative Name Server Groups

To add an authoritative name server group:

1. From the Data Management -> DNS tab, do one of the following:

   • Click the Name Server Groups tab -> Add icon -> Group -> Authoritative.

   • From the Toolbar, click the Add icon -> Group -> Authoritative.

2. In the Add Name Server Group wizard, do the following:

   • Name: Type a name that provides a meaningful reference for this set of servers.

   • Name Servers: Click the Add icon and select one of the following options for every server that you are adding to the NS group:

     • Grid Primary: Choose this option to select a primary name server or multiple primary servers for the zone. See Specifying Grid Primary Servers.

     • Grid Secondary: Choose this option to select a Grid member as a secondary server for the zone. See Adding Grid Secondaries.

     • External Primary: Choose this option if the appliance is in a Grid and you want to specify a primary server outside the Grid ("external" to the Grid). See Specifying External Primary Servers.

     • External Secondary: Choose this option if the appliance is in a Grid and you want to specify a secondary server outside the Grid ("external" to the Grid), or if the appliance is deployed independently from a Grid. See Specifying External Secondaries.

   • Default NS Group: Select this to specify this authoritative name server group as the default.

   • Comment: Optionally, enter additional information about the authoritative NS group.

3. Save the configuration and click Restart if it appears at the top of the screen, or click Next to define extensible attributes. For information, see Using Extensible Attributes.
A newly created authoritative name server group appears in the Name Server Groups tab. For information about viewing the name server groups, see Viewing Name Server Groups. You can then associate it with forward-mapping and reverse-mapping authoritative zones.

Applying Authoritative Name Server Groups

In Grid Manager, you can assign an authoritative name server group to an authoritative zone when you first create it using the Add Authoritative Zone wizard and when you edit an existing authoritative zone using the Authoritative Zone editor. For information on creating an authoritative zone using the wizard, see Configuring Authoritative Zones. The panels used to assign a name server group to a zone are the same in the wizard or and editor. The only difference is the way you access it. The following procedure describes how to specify an authoritative NS group when editing a forward-mapping zone:

1. From the Data Management tab -> DNS tab -> Zones tab -> zone checkbox, and then click the Edit icon.

2. In the Authoritative Zone editor, click Name Servers.

3. Select Use this name server group, and then select the authoritative NS group from the drop-down list.

Using Delegation Name Server Groups

A delegation name server group is a collection of external name servers for delegated zones. Adding a set of external name servers to a single delegation name server group can significantly reduce configuration efforts. While configuring delegated zones, you can specify a single delegation NS group instead of configuring multiple name servers individually. After you create a delegation NS group, you can then assign it to serve only delegated zones. When you assign a delegation NS group to a delegated zone, Grid Manager automatically generates an NS record, a glue A or AAAA record, and a PTR record for each name server available in the delegation NS group. But if the zone is disabled, Grid Manager does not generate these records.
Note the following while adding a delegation NS group:

• You cannot add a delegation NS group if a NS group with the same name already exists and vice versa.

• If a Grid has any Microsoft servers configured, delegation NS groups are not allowed and vice versa.

• You cannot delete a delegation NS group if it is assigned to a zone.

• The DNS server resolves the FQDN of the delegated name server and does not use the IP address that you specify when assigning the delegated name servers. 

Adding Delegation Name Server Groups

To add a delegation name server group:

1. From the Data Management -> DNS tab, do one of the following:

   • Click the Name Server Groups tab -> Add icon -> Delegation.

   • From the Toolbar, click the Add icon -> Group -> Delegation.

2. In the Add Delegation Name Server Group wizard, complete the following:

   • Name: Enter the name of the delegation NS group.

   • Comment: Optionally, enter additional information about the delegation NS group.

3. Click Next to define the external name servers for the delegation NS group.

4. In the Name Server panel, click the Add icon and specify the following for every server that you are adding to the delegation NS group:

   • Name: Enter the name of the delegated name server.

   • Address: Enter the IP address of the delegated name server.

5. Save the configuration and click Restart if it appears at the top of the screen, or click Next to define extensible attributes. For information, see Using Extensible Attributes.
   A newly created delegation NS group appears in the Name Server Groups tab. For information about viewing the name server groups, see Viewing Name Server Groups. You can then associate it with delegated zones.

Applying Delegation Name Server Groups

You can assign a delegation NS group to a delegated zone when you first create it using the Add Delegation wizard and when you edit an existing delegated zone using the Delegation Zone editor. For information about creating a delegated zone using the wizard, see Configuring a Delegation.
Complete the following to assign a delegation NS group to a delegation zone:

1. From the Data Management tab -> DNS tab -> Zones tab -> delegation zone checkbox, and then click the Edit icon.

2. In the Delegation Zone editor, click Delegated Name Servers.

3. Select Use this name server group, and then select the delegation NS group from the drop-down list.

Using Forwarding Member Name Server Groups

A forwarding member NS (Name Server) group is a collection of one or more forwarding name servers. Grouping a set of forwarding name servers together reduces the configuration efforts. When you configure a forwarding zone, you can specify a single forwarding member NS group instead of specifying multiple forwarding name servers individually. After you create a forwarding member NS group, you can assign it to a forward forward-mapping zone and a forward reverse-mapping zone.
Note the following while adding a forwarding member NS group:

• Only superusers can add, modify, and delete a forwarding member NS group.

• You cannot add a forwarding member NS group if a NS group with the same name already exists and vice versa.

• You cannot delete a forwarding member NS group if it is assigned to a zone.

Adding Forwarding Member Name Server Groups

To add a forwarding member NS group:

1. From the Data Management -> DNS tab, do one of the following:

   • Click the Name Server Groups tab -> Add icon -> Forwarding Member.

   • From the Toolbar, click the Add icon -> Group -> Forwarding Member.

2. In the Forwarding Member Name Server Group wizard, complete the following:

   • Name: Enter the name of the forwarding member NS group.

   • Name Servers: In this section, you can add the Grid members to the forwarding member NS group and use the default forwarders or you can override default forwarders and configure custom forwarders. Click the Add icon and select a Grid member from the MemberSelector dialog box.
     The following is displayed in the table for each member:

     • Name: The name of the Grid member.

     • IPv4 Address: The IPv4 address of the Grid member.

     • IPv6 Address: The IPv6 address of the Grid member.

     • Override Default Forwarders: Displays Yes when you override default forwarders. Otherwise, this field displays No.

     • Custom Forwarders: Displays the IP address of the custom forwarders. Otherwise, this field is blank.

   • Comment: Optionally, enter additional information about the forwarding member NS group.

3. Save the configuration or click Next to define extensible attributes. For information, see Using Extensible Attributes.

A newly created forwarding member NS group appears in the Name Server Groups tab. For information about viewing the name server groups, see Viewing Name Server Groups. You can then associate it with forward forward-mapping zones and forward reverse-mapping zones.

Applying Forwarding Member Name Server Groups

You can assign a forwarding member NS group to a forward zone when you first create it using the Add Forward Zone wizard and when you edit an existing forward zone using the Forward Zone editor. For information about creating a forward zone using the wizard, see Configuring a Forward Zone.
Complete the following to assign a forwarding member NS group to a forward zone:

1. From the Data Management tab -> DNS tab -> Zones tab -> forward zone checkbox, and then click the Edit icon.

2. In the Forward Zone editor, click Name Servers.

3. Select Use this name server group, and then select the forwarding member NS group from the drop-down list.

Using Stub Member Name Server Groups

A stub member NS (Name Server) Group is a collection of one or more Grid members for stub zones. When you configure a stub zone, you can specify a single stub member NS group instead of specifying multiple Grid members individually, thus reducing the configuration efforts. After you create a stub member NS group, you can assign it to forward-mapping stub zones and reverse-mapping stub zones.
Note the following while adding a stub member NS group:

• Only superusers can add, modify, and delete a stub member NS group.

• You cannot add a stub member NS group if a NS group with the same name already exists and vice versa.

• You cannot delete a stub member NS group if it is assigned to a zone.

Adding Stub Member Name Server Groups

To add a stub member NS group:

1. From the Data Management -> DNS tab, do one of the following:

   • Click the Name Server Groups tab -> Add icon -> Stub Member.

   • From the Toolbar, click the Add icon -> Group -> Stub Member.

2. In the Stub Member Name Server Group wizard, complete the following:

   • Name: Enter the name of the stub member NS group.

   • Name Servers: In this section, you can add the Grid members to the stub member NS group. Click the Add icon and select a Grid member from the MemberSelector dialog box.
     The following is displayed in the table for each member:

     • Name: The name of the Grid member.

     • IPv4 Address: The IPv4 address of the Grid member.

     • IPv6 Address: The IPv6 address of the Grid member.

   • Comment: Optionally, enter additional information about the stub member NS group.

3. Save the configuration or click Next to define extensible attributes. For information, see Using Extensible Attributes.

A newly created stub member NS group appears in the Name Server Groups tab. For information about viewing the name server groups, see Viewing Name Server Groups. You can then associate it with stub
forward-mapping zones and stub reverse-mapping zones.

Applying Stub Member Name Server Groups

You can assign a stub member NS group to a stub zone when you first create it using the Add Stub Zone wizard and when you edit an existing stub zone using the Stub Zone editor. For information about creating a stub zone using the wizard, see Configuring Stub Zones.
Complete the following to assign a stub member NS group to a stub zone:

1. From the Data Management tab -> DNS tab -> Zones tab -> stub zone checkbox, and then click the Edit icon.

2. In the Stub Zone editor, click Name Servers.

3. Select Use this name server group, and then select the stub member NS group from the drop-down list.

Using Forward/Stub Server Name Server Groups

A forward/stub server NS (Name Server) group is a collection of one or more external name servers. Grouping a set of external name servers together to a forward/stub server NS group reduces the configuration efforts. You can assign a single forward/stub server NS group as default forwarders for a forward zone or as primary servers for a stub zone instead of specifying multiple name servers individually.
Note the following while adding a forward/stub server NS group:

• Only super-users can add, modify, and delete a forward/stub server NS group.

• You cannot add a forward/stub server NS group if a NS group with the same name already exists and vice versa.

• You cannot delete a forward/stub server NS group if it is assigned to a zone.

Adding Forward/Stub Server Name Server Groups

To add a forward/stub server NS group:

1. From the Data Management -> DNS tab, do one of the following:

   • Click the Name Server Groups tab -> Add icon -> Forward/Stub Server.

   • From the Toolbar, click the Add icon -> Group -> Forward/Stub Server.

2. In the Forward/Stub Server Name Server Group wizard, complete the following:

   • Name: Enter a name that provides a meaningful reference for this set of external name servers for the forward and stub zones.

   • Name Servers: Click the Add icon and specify the following for every external name server that you are adding to the forward/stub server NS group:

     • Name: The name of the external name server.

     • IP Address: The IP address of the external name server.

   • Comment: Optionally, enter additional information about the forward/stub server NS group.

3. Save the configuration or click Next to define extensible attributes. For information, see Using Extensible Attributes.

A newly created forward/stub server NS group appears in the Name Server Groups tab. For information about viewing the name server groups, see Viewing Name Server Groups. You can then associate it with forward zones as default forwarders and as primary servers for stub zones.

Applying Forward/Stub Server Name Server Groups

You can assign a forward/stub server NS group to a forward zone as default forwarders and as primary servers to a stub zone when you first create it and when you edit an existing forward zone and stub zone. For information about creating a forward zone using the wizard, see Configuring a Forward Zone. For information about creating a stub zone using the wizard, see Configuring Stub Zones.
Complete the following to assign a forward/stub server NS group to a forward zone:

1. From the Data Management tab -> DNS tab -> Zones tab -> forward zone checkbox, and then click the Edit icon.

2. In the Forward Zone editor, click Forwarders.

3. Select Use this name server group, and then select the forward/stub server NS group from the drop-down list. Complete the following to assign a forward/stub server NS group to a stub zone:

4. From the Data Management tab -> DNS tab -> Zones tab -> stub zone checkbox, and then click the Edit icon.

5. In the Stub Zone editor, click Masters.

6. Select Use this name server group, and then select the forward/stub server NS group from the drop-down list.