---
title: "Configuring DHCP for DDNS"
canonical: "https://docs.infoblox.com/space/nios85/35418670/Configuring%20DHCP%20for%20DDNS"
format: markdown
---
Before a DHCP server can update DNS, the DHCP server needs to have an FQDN-to-IP address mapping. When a DHCP IPv4 client requests an IP address, it typically includes its host name in option 12 of the DHCPDISCOVER packet, and an IPv6 client includes its hostname in the Request packet. You can configure the NIOS appliance to include a domain name in option 15 of the IPv4 DHCPOFFER packet or in the IPv6 Reply packet. You specify this domain name in the **IPv4** **DHCP** **Options** -> **Basic** and **IPv6** **DHCP** **Options** -> **Basic** tabs of the *Grid* *DHCP* *Properties* editor, *Member* *DHCP* *Configuration* editor, and the *Network* *editor.* For IPv4 clients you can also specify a domain name in the *DHCP* *Range* and *Fixed*> Macro (anchor)

 *Address* editors.  
Then, you can enable the DHCP server to send DDNS updates for IPv4 and IPv6 clients, as described in *<span style="color: #0000ff">[Enabling](https://infoblox-docs.atlassian.net/wiki/spaces/nios85draft/pages/26478343)</span>*[ ](https://infoblox-docs.atlassian.net/wiki/spaces/nios85draft/pages/26478343)*<span style="color: #0000ff">[DDNS](https://infoblox-docs.atlassian.net/wiki/spaces/nios85draft/pages/26478343)</span>*[ ](https://infoblox-docs.atlassian.net/wiki/spaces/nios85draft/pages/26478343)*<span style="color: #0000ff">[for](https://infoblox-docs.atlassian.net/wiki/spaces/nios85draft/pages/26478343)</span>*[ ](https://infoblox-docs.atlassian.net/wiki/spaces/nios85draft/pages/26478343)*<span style="color: #0000ff">[IPv4](https://infoblox-docs.atlassian.net/wiki/spaces/nios85draft/pages/26478343)</span>*[ ](https://infoblox-docs.atlassian.net/wiki/spaces/nios85draft/pages/26478343)*<span style="color: #0000ff">[and](https://infoblox-docs.atlassian.net/wiki/spaces/nios85draft/pages/26478343)</span>*[ ](https://infoblox-docs.atlassian.net/wiki/spaces/nios85draft/pages/26478343)*<span style="color: #0000ff">[IPv6](https://infoblox-docs.atlassian.net/wiki/spaces/nios85draft/pages/26478343)</span>*[ ](https://infoblox-docs.atlassian.net/wiki/spaces/nios85draft/pages/26478343)*<span style="color: #0000ff">[DHCP](https://infoblox-docs.atlassian.net/wiki/spaces/nios85draft/pages/26478343)</span>*[ ](https://infoblox-docs.atlassian.net/wiki/spaces/nios85draft/pages/26478343)*<span style="color: #0000ff">[Clients](https://infoblox-docs.atlassian.net/wiki/spaces/nios85draft/pages/26478343)</span>*. After you enable the DHCP server to send DDNS updates, you can do the following:

- Configure the DHCP server to send DDNS updates to DNS servers in the Grid. For information, see *<span style="color: #0000ff">[Sending](https://infoblox-docs.atlassian.net/wiki/spaces/nios85draft/pages/26478343)</span>*[ ](https://infoblox-docs.atlassian.net/wiki/spaces/nios85draft/pages/26478343)*<span style="color: #0000ff">[Updates](https://infoblox-docs.atlassian.net/wiki/spaces/nios85draft/pages/26478343)</span>*[ ](https://infoblox-docs.atlassian.net/wiki/spaces/nios85draft/pages/26478343)*<span style="color: #0000ff">[to](https://infoblox-docs.atlassian.net/wiki/spaces/nios85draft/pages/26478343)</span>*[ ](https://infoblox-docs.atlassian.net/wiki/spaces/nios85draft/pages/26478343)*<span style="color: #0000ff">[DNS](https://infoblox-docs.atlassian.net/wiki/spaces/nios85draft/pages/26478343)</span>*[ ](https://infoblox-docs.atlassian.net/wiki/spaces/nios85draft/pages/26478343)*<span style="color: #0000ff">[Servers](https://infoblox-docs.atlassian.net/wiki/spaces/nios85draft/pages/26478343)</span>*[ ](https://infoblox-docs.atlassian.net/wiki/spaces/nios85draft/pages/26478343)*<span style="color: #0000ff">[in](https://infoblox-docs.atlassian.net/wiki/spaces/nios85draft/pages/26478343)</span>*[ ](https://infoblox-docs.atlassian.net/wiki/spaces/nios85draft/pages/26478343)*<span style="color: #0000ff">[the](https://infoblox-docs.atlassian.net/wiki/spaces/nios85draft/pages/26478343)</span>*[ ](https://infoblox-docs.atlassian.net/wiki/spaces/nios85draft/pages/26478343)*<span style="color: #0000ff">[Grid](https://infoblox-docs.atlassian.net/wiki/spaces/nios85draft/pages/26478343)</span>*.
- Configure the DHCP server to send DDNS updates to external DNS servers. For information, see *<span style="color: #0000ff">[Configuring](https://infoblox-docs.atlassian.net/wiki/spaces/nios85/pages/35882016)</span>* *<span style="color: #0000ff">[DDNS](https://infoblox-docs.atlassian.net/wiki/spaces/nios85/pages/35882016)</span>*[ ](https://infoblox-docs.atlassian.net/wiki/spaces/nios85/pages/35882016)*<span style="color: #0000ff">[Features](https://infoblox-docs.atlassian.net/wiki/spaces/nios85/pages/35882016)</span>*.
- Configure certain DDNS features. For information, see *<span style="color: #0000ff">[Configuring](https://infoblox-docs.atlassian.net/wiki/spaces/nios85/pages/35882016/Configuring+DDNS+Features#ConfiguringDDNSFeatures-bookmark1937)</span>*[ ](https://infoblox-docs.atlassian.net/wiki/spaces/nios85/pages/35882016/Configuring+DDNS+Features#ConfiguringDDNSFeatures-bookmark1937)*<span style="color: #0000ff">[DDNS](https://infoblox-docs.atlassian.net/wiki/spaces/nios85/pages/35882016/Configuring+DDNS+Features#ConfiguringDDNSFeatures-bookmark1937)</span>*[ ](https://infoblox-docs.atlassian.net/wiki/spaces/nios85/pages/35882016/Configuring+DDNS+Features#ConfiguringDDNSFeatures-bookmark1937)*<span style="color: #0000ff">[Features](https://infoblox-docs.atlassian.net/wiki/spaces/nios85/pages/35882016/Configuring+DDNS+Features#ConfiguringDDNSFeatures-bookmark1937)</span>*.
- Enable support for the FQDN option for IPv4 and IPv6 clients, and configure how the DHCP server updates DNS. For information, see *<span style="color: #0000ff">[Enabling](https://infoblox-docs.atlassian.net/wiki/spaces/nios85/pages/35849567/About+the+Client+FQDN+Option#AbouttheClientFQDNOption-bookmark1944)</span>*[ ](https://infoblox-docs.atlassian.net/wiki/spaces/nios85/pages/35849567/About+the+Client+FQDN+Option#AbouttheClientFQDNOption-bookmark1944)*<span style="color: #0000ff">[FQDN](https://infoblox-docs.atlassian.net/wiki/spaces/nios85/pages/35849567/About+the+Client+FQDN+Option#AbouttheClientFQDNOption-bookmark1944)</span>*[ ](https://infoblox-docs.atlassian.net/wiki/spaces/nios85/pages/35849567/About+the+Client+FQDN+Option#AbouttheClientFQDNOption-bookmark1944)*<span style="color: #0000ff">[Option](https://infoblox-docs.atlassian.net/wiki/spaces/nios85/pages/35849567/About+the+Client+FQDN+Option#AbouttheClientFQDNOption-bookmark1944)</span>*[ ](https://infoblox-docs.atlassian.net/wiki/spaces/nios85/pages/35849567/About+the+Client+FQDN+Option#AbouttheClientFQDNOption-bookmark1944)*<span style="color: #0000ff">[Support](https://infoblox-docs.atlassian.net/wiki/spaces/nios85/pages/35849567/About+the+Client+FQDN+Option#AbouttheClientFQDNOption-bookmark1944)</span>*[.](https://infoblox-docs.atlassian.net/wiki/spaces/nios85/pages/35849567/About+the+Client+FQDN+Option#AbouttheClientFQDNOption-bookmark1944)

> ⚠️ **Note**
> ⚠️ 
> ⚠️ Whether you deploy NIOS appliance in a Grid or independently, they send updates to UDP port 53. Grid members do not send updates through a VPN tunnel; however, Grid members do authenticate updates between each other using TSIG (transaction signatures) based on an internal TSIG key.


# > Macro (anchor)

> Macro (anchor)

> Macro (anchor)

Enabling DDNS for IPv4 and IPv6 DHCP Clients

You can enable the DHCP server to send DDNS updates for IPv4 clients at the Grid, member, shared network, network, address range, DHCP template, fixed address, and roaming host levels, and for IPv6 clients at the Grid, member, network, shared network, network template and roaming host levels.  
You can specify a different domain name that the appliance uses specifically for DDNS updates. The appliance combines the hostname from the client and the domain name you specify to create the FQDN that it uses to update DNS. For IPv4 clients, you can specify the DDNS domain name at the network, network template, range, and range template levels. For IPv6 clients, you can specify the DDNS domain name at the Grid, member, network, shared network, and network template levels. You can also use the name of a roaming host record as the name of the client for DDNS updates, as described in *<span style="color: #0000ff">[Setting](https://infoblox-docs.atlassian.net/wiki/spaces/nios85/pages/35385621/About+Roaming+Hosts#AboutRoamingHosts-bookmark2394)</span>*[ ](https://infoblox-docs.atlassian.net/wiki/spaces/nios85/pages/35385621/About+Roaming+Hosts#AboutRoamingHosts-bookmark2394)*<span style="color: #0000ff">[Properties](https://infoblox-docs.atlassian.net/wiki/spaces/nios85/pages/35385621/About+Roaming+Hosts#AboutRoamingHosts-bookmark2394)</span>*[ ](https://infoblox-docs.atlassian.net/wiki/spaces/nios85/pages/35385621/About+Roaming+Hosts#AboutRoamingHosts-bookmark2394)*<span style="color: #0000ff">[for](https://infoblox-docs.atlassian.net/wiki/spaces/nios85/pages/35385621/About+Roaming+Hosts#AboutRoamingHosts-bookmark2394)</span>*[ ](https://infoblox-docs.atlassian.net/wiki/spaces/nios85/pages/35385621/About+Roaming+Hosts#AboutRoamingHosts-bookmark2394)*<span style="color: #0000ff">[Roaming](https://infoblox-docs.atlassian.net/wiki/spaces/nios85/pages/35385621/About+Roaming+Hosts#AboutRoamingHosts-bookmark2394)</span>*[ ](https://infoblox-docs.atlassian.net/wiki/spaces/nios85/pages/35385621/About+Roaming+Hosts#AboutRoamingHosts-bookmark2394)*<span style="color: #0000ff">[Hosts](https://infoblox-docs.atlassian.net/wiki/spaces/nios85/pages/35385621/About+Roaming+Hosts#AboutRoamingHosts-bookmark2394)</span>*.  
To enable DDNS and specify a DDNS domain name:

1. **Grid:** From the **Data****Management** tab, select the **DHCP** tab, expand the Toolbar and click **Grid****DHCP****Properties**.   
**Member**: From the **Data****Management** tab, select the **DHCP** tab and click the **Members** tab -> **Members** -> *member *checkbox -> Edit icon.  
**Network**: From the **Data****Management** tab, select the **DHCP** tab and click the **Networks** tab -> **Networks** -> *network* checkbox -> Edit icon.  
**Network****Container**: From the **Data****Management** tab, select the **IPAM** tab -> *network_container* checkbox, and then click the Edit icon.   
**Network****Template**: From the **Data****Management** tab, select the **DHCP** tab and click the **Templates** tab -> *DHCP_template* checkbox -> Edit icon.  
**Roaming****Host**: From the **Data****Management** tab, select the **DHCP** tab and click the **Networks** tab -> **Roaming****Hosts** -> *roaming_host* -> Edit icon.  
For IPv4 clients only:**IPv4****Address****Range**: From the **Data****Management** tab, select the **DHCP** tab and click the **Networks** tab -> **Networks** -> *network* -> *addr_range* checkbox -> Edit icon.   
**IPv4****Fixed****Address**: From the **Data****Management** tab, select the **DHCP** tab and click the **Networks** tab -> **Networks** -> *network* -> *ip_addr* checkbox -> Edit icon.  
**IPv4****Address****Range**/**Fixed****Address****Template**: From the **Data****Management** tab, select the **DHCP** tab and click the **Templates** tab -> *DHCP_template* checkbox -> Edit icon.  
To override an inherited property, click **Override** next to it and complete the appropriate fields.
2. In the **IPv4****DDNS** -> **Basic** tab or the **IPv6****DDNS** -> **Basic** tab, complete the following:
  - **Enable ****DDNS ****Updates**: Select this checkbox to enable DDNS updates.

> ⚠️ **Note**
> ⚠️ 
> ⚠️ In a dual mode Grid, if IPv6 DDNS updates is enabled at the Grid level, then when you join an IPv6 Grid member to the Grid, IPv6 DDNS updates is automatically disabled for the Grid member.

> Macro (legacy-content)

     3. Save the configuration and click **Restart** if it appears at the top of the screen.

# > Macro (anchor)

> Macro (anchor)

Sending Updates to DNS Servers

The DHCP server can send DDNS updates to DNS servers in the same Grid and to external DNS servers. When you enable the appliance to send updates to Grid members, you must specify the DNS view to be updated. If a network view has multiple DNS views, you can select only one DNS view for DDNS updates. For information about DNS views, see *<span style="color: #0000ff">[About DNS](https://infoblox-docs.atlassian.net/wiki/spaces/nios85/pages/35881237/About+DNS+Views#AboutDNSViews-bookmark1681)</span>*[ ](https://infoblox-docs.atlassian.net/wiki/spaces/nios85/pages/35881237/About+DNS+Views#AboutDNSViews-bookmark1681)*<span style="color: #0000ff">[Views](https://infoblox-docs.atlassian.net/wiki/spaces/nios85/pages/35881237/About+DNS+Views#AboutDNSViews-bookmark1681)</span>*.  
When you enable DDNS updates for a Grid, member, shared network, network, address range, DHCP template, fixed address, or roaming host, the DHCP server sends updates to authoritative zones using the domain name (as DHCP option 15) you define in the DHCP properties. You can also define forward-mapping zones that receive DDNS updates for DHCP clients that use option 81 to define the domain name. For information, see *<span style="color: #0000ff">[About](https://infoblox-docs.atlassian.net/wiki/spaces/nios85/pages/35849567)</span>*[ ](https://infoblox-docs.atlassian.net/wiki/spaces/nios85/pages/35849567)*<span style="color: #0000ff">[the](https://infoblox-docs.atlassian.net/wiki/spaces/nios85/pages/35849567)</span>*[ ](https://infoblox-docs.atlassian.net/wiki/spaces/nios85/pages/35849567)*<span style="color: #0000ff">[Client](https://infoblox-docs.atlassian.net/wiki/spaces/nios85/pages/35849567)</span>*[ ](https://infoblox-docs.atlassian.net/wiki/spaces/nios85/pages/35849567)*<span style="color: #0000ff">[FQDN](https://infoblox-docs.atlassian.net/wiki/spaces/nios85/pages/35849567)</span>*[ ](https://infoblox-docs.atlassian.net/wiki/spaces/nios85/pages/35849567)*<span style="color: #0000ff">[Option](https://infoblox-docs.atlassian.net/wiki/spaces/nios85/pages/35849567)</span>*. To allow DDNS updates for clients using option 81, you must first enable the support for option 81. For information, see *<span style="color: #0000ff">[Configuring](https://infoblox-docs.atlassian.net/wiki/spaces/nios85/pages/35882016)</span>*[ ](https://infoblox-docs.atlassian.net/wiki/spaces/nios85/pages/35882016)*<span style="color: #0000ff">[DDNS](https://infoblox-docs.atlassian.net/wiki/spaces/nios85/pages/35882016)</span>*[ ](https://infoblox-docs.atlassian.net/wiki/spaces/nios85/pages/35882016)*<span style="color: #0000ff">[Features](https://infoblox-docs.atlassian.net/wiki/spaces/nios85/pages/35882016)</span>*.   
    
For DNS zones that have multiple primary servers, you can define a primary name server to be used as the default primary server when performing DDNS updates from the appliance. Note that you cannot configure an external primary as the default primary. For more information, see *<span style="color: #0000ff">[Defining](https://infoblox-docs.atlassian.net/wiki/spaces/nios85draft/pages/26478343)</span>*[ ](https://infoblox-docs.atlassian.net/wiki/spaces/nios85draft/pages/26478343)*<span style="color: #0000ff">[the](https://infoblox-docs.atlassian.net/wiki/spaces/nios85draft/pages/26478343)</span>*[ ](https://infoblox-docs.atlassian.net/wiki/spaces/nios85draft/pages/26478343)*<span style="color: #0000ff">[Default](https://infoblox-docs.atlassian.net/wiki/spaces/nios85draft/pages/26478343)</span>*[ ](https://infoblox-docs.atlassian.net/wiki/spaces/nios85draft/pages/26478343)*<span style="color: #0000ff">[Primary](https://infoblox-docs.atlassian.net/wiki/spaces/nios85draft/pages/26478343)</span>*[ ](https://infoblox-docs.atlassian.net/wiki/spaces/nios85draft/pages/26478343)*<span style="color: #0000ff">[for](https://infoblox-docs.atlassian.net/wiki/spaces/nios85draft/pages/26478343)</span>*[ ](https://infoblox-docs.atlassian.net/wiki/spaces/nios85draft/pages/26478343)*<span style="color: #0000ff">[DDNS](https://infoblox-docs.atlassian.net/wiki/spaces/nios85draft/pages/26478343)</span>*[ ](https://infoblox-docs.atlassian.net/wiki/spaces/nios85draft/pages/26478343)*<span style="color: #0000ff">[Updates](https://infoblox-docs.atlassian.net/wiki/spaces/nios85draft/pages/26478343)</span>*[ ](https://infoblox-docs.atlassian.net/wiki/spaces/nios85draft/pages/26478343)*<span style="color: #0000ff">[to](https://infoblox-docs.atlassian.net/wiki/spaces/nios85draft/pages/26478343)</span>*[ ](https://infoblox-docs.atlassian.net/wiki/spaces/nios85draft/pages/26478343)*<span style="color: #0000ff">[Zones](https://infoblox-docs.atlassian.net/wiki/spaces/nios85draft/pages/26478343)</span>* *<span style="color: #0000ff">[with](https://infoblox-docs.atlassian.net/wiki/spaces/nios85draft/pages/26478343)</span>*[ ](https://infoblox-docs.atlassian.net/wiki/spaces/nios85draft/pages/26478343)*<span style="color: #0000ff">[Multiple](https://infoblox-docs.atlassian.net/wiki/spaces/nios85draft/pages/26478343)</span>*[ ](https://infoblox-docs.atlassian.net/wiki/spaces/nios85draft/pages/26478343)*<span style="color: #0000ff">[Primaries](https://infoblox-docs.atlassian.net/wiki/spaces/nios85draft/pages/26478343)</span>*.

## > Macro (anchor)

Sending Updates to DNS Servers in the> Macro (anchor)

 Grid

You must specify the DNS view to be updated for each network view.  
To configure the DHCP server to send updates to DNS servers in the same Grid:

1. If there are multiple network views in the Grid, select a network view.
2. From the **Data ****Management** tab, select the **DHCP** tab, and then click **Configure**** DDNS** from the Toolbar.
3. In the *DDNS* *Properties* editor, complete the following:

> Macro (legacy-content)

      4. Save the configuration and click **Restart** if it appears at the top of the screen.

The appliance sends DDNS updates to the appropriate zones in the selected DNS view. Note that you cannot delete a DNS view that has been selected for DDNS updates. By default, the DHCP server sends DDNS updates to zones using the domain name that you define for DHCP objects, such as networks and DHCP ranges.

## > Macro (anchor)

Sending Updates for Zones on an External Name Server

The DHCP server can send dynamic updates to an external name server that you specify. For each network view, you can specify the zone to be updated and the IP address of the primary name server for that zone. You can add information for a forward and reverse zone. The DHCP server updates the A record in the forward zone and the PTR record in the reverse zone.  
You can also use TSIG (transaction signatures) or GSS-TSIG to secure communications between the servers. TSIG uses the MD5 (Message Digest 5) algorithm and a shared secret key to create an HMAC (hashed message authentication code)—sometimes called a digital fingerprint—of each update. Both the DHCP server sending the update and the DNS server receiving it must share the same secret key. Also, it is important that the time stamps on the TSIG-authenticated updates and update responses be synchronized, or the participants reject them. Therefore, use an NTP server to set the time on all systems involved in TSIG authentication operations.  
Note that only a superuser can configure DDNS. To configure DDNS, a limited-access admin must contact a superuser.

To send updates to a DNS server that is external to your Grid:

1. If there are multiple network views in the Grid, select a network view.
2. From the **Data**** Management** tab, select the **DHCP** tab, expand the Toolbar and click **Configure**** DDNS**.
3. In the **DDNS**** Updates ****to**** External ****Zones** section of the *DDNS** Properties* editor, click the Add icon. Complete the following fields in the Add External DDNS Zone panel, and then click** Add**:
  - **Zone**** Name:** Enter the FQDN of a valid forward-mapping or reverse-mapping zone to which the DHCP server sends the updates. Do not enter the zone name in CIDR format. To specify a zone name in IDN, manually convert IDN to punycode and use the punycode representation.
  - **DNS**** Server**** Address:** Enter the IP address of the primary name server for that zone.
  - **Security:** Select one of the following security methods:
    - **None:** Select this to use unsecured DDNS updates. This is the default.
    - **TSIG:** Select this to use the standards-based TSIG key that uses the one-way hash function MD5 to secure transfers between name servers. You can either specify an existing key or generate a new key.  
To specify an existing key, complete the following:  
**Key**** Name:** Enter the TSIG key name. The key name entered here must match the TSIG key name on the external name server.  
**Key ****Algorithm:** Select either **HMAC-MD5** or **HMAC-SHA256.**  
**Key**** Data:** To use an existing TSIG key, type or paste the key in the **Key**** Data** field. Alternatively, you can select the key algorithm, select the key length from the **Generate****Key****Data** drop down list, and then click **Generate**** Key ****Data** to create a new key.
    - **GSS-TSIG:** For information about using GSS-TSIG, see *<span style="color: #0000ff">[About](https://infoblox-docs.atlassian.net/wiki/spaces/nios85/pages/35784032)</span>*[ ](https://infoblox-docs.atlassian.net/wiki/spaces/nios85/pages/35784032)*<span style="color: #0000ff">[GSS-TSIG](https://infoblox-docs.atlassian.net/wiki/spaces/nios85/pages/35784032)</span>*.

       4. Save the configuration and click **Restart** if it appears at the top of the screen.

## > Macro (anchor)

> Macro (anchor)

Defining the Default Primary for DDNS Updates to Zones with Multiple Primaries

If you have configured multiple primary servers for an authoritative zone, you can define the default primary that the appliance uses to perform DDNS updates for the zone. Note that you can configure a Grid primary, but not an external primary, as the default primary. If you do not configure a default primary, the Grid Master becomes the default primary for the zones that it serves. Otherwise, the appliance selects a primary server that serves the zone as the default primary. For external zones that have multiple primaries, the first external primary server becomes the default primary.

Configuring a default primary for DDNS updates is useful when you have DHCP members that span across different locations. Performing DDNS updates becomes more efficient when you configure a default primary that is close in proximity to the DHCP member. For example, zone corpxyz.com has two primaries (usa.corpxyz.com and japan.corpxyz.com) serving two locations (USA and Japan). Service performance is faster when you select usa.corpxyz.com as the default primary for DDNS updates in the USA region and japan.corpxyz.com as the default primary for the Japan region.

When you configure a preferred or default primary server for DDNS updates to a zone that has multiple primaries, ensure that the following are in place:

- The zone that you select contains multiple primary servers.
- The primary server has DNS service enabled and is authoritative for the zone.
- The appliance has DHCP service enabled.

> ⚠️ **Note**
> ⚠️ 
> ⚠️ You can define the default primary for the Grid and override the setting at the member level, and you must restart service for the configuration to take effect. Primary selection is performed at service restart, not at runtime.


To define the default primary:

1. **Grid:** From the **Data** **Management** tab, select the **DHCP** tab, expand the Toolbar and click **Configure** **DDNS**. In the DDNS Properties editor, scroll down to the **Master** **Preferences** **for** **DDNS** **Updates** **to** **Multi-master** **DNS** **Zones** section.  
**Member**: From the **Data** **Management** tab, select the **DHCP** tab and click the **Members** tab -> *member* checkbox -> Edit icon. In the *Member* *DHCP* *Properties* editor, select the **DDNS** tab.
2. In the **Master** **Preferences** **for** **DDNS** **Updates** **to** **Multi-master** **DNS** **Zones** section, click the Add icon and select one of the following from the list:
  - **Grid** **Zone**: In the Add Grid Zone panel, complete the following:
    - **Zone**: Click **Select** **Zone** to select the zone that has multiple primaries. Note that when configuring for the Grid, only zones that belong to the selected DNS view are displayed in the *Zone* *Selector* dialog box. For a Grid member however, if it is associated with a network view or if you have defined a DNS view for DDNS updates for that network view, only zones that belong to the DNS view configured for the associated network view are displayed.
    - **DNS** **View**: Displays the DNS view to which this zone belongs.
    - **DNS** **Primary**: From the drop-down list, select the primary name server you want the appliance to use when performing DDNS updates. Note that the list displays only primary servers that are defined for the selected zone.
  - **Default** **Primary**: In the Add Default Primary panel, complete the following:
    - **DNS** **Primary**: Click **Select** to select a primary name server from the *Member* *Selector* dialog. When you select a default primary, the appliance uses this name server for DDNS updates to all zones.
3. Click **Add** to add the zone and primary name server to the table, which displays the following information:
  - **DNS** **View**: The DNS view to which the zone belongs.
  - **Zone**: The selected zone that has multiple primaries.
  - **DNS** **Primary**: The primary server to be used when performing DDNS updates from a NIOS DHCP server to the selected zone.
  
4. **Concatenated** **with** **the** **following** **rules** **defined** **at** **the** **Grid** **level**: This section appears only in the *Member* *DHCP* *Properties* editor. This table displays rules that are defined for zones with multiple primaries at the Grid level. Rules configured at the member level automatically override those configured for the Grid. Note that all rules configured for both the Grid and the member apply.