If you have split DNS server configuration (for example, environments that maintain private internal DNS servers and external DNS servers) you can choose to add servers to an Alternate DNS server group as well as to the Primary DNS server group. In addition, you can create custom DNS server groups.In the ProxySG, internal DNS servers are placed in the Primary group, while external DNS servers (with the Internet information) populate the Alternate group.
The following rules apply to DNS server groups:
-You can add servers to the Primary and Alternate groups, but you cannot change the domain or add additional domains; these groups are defined at initial configuration.
-The Primary and Alternate DNS groups cannot be deleted.
-A custom DNS group must have at least one server in order to add domains.
To configure DNS servers groups:
- Open management console
- Go to Configuration> Network> DNS
- Go to Groups
- In Primary group put all your internal DNS servers
- If you have external servers put them in Alternate group
- Click on Apply.
To create a custom group:
1. Select Configuration > Network > DNS > Groups. The list of DNS groups displays.
2. Click New. The Create DNS Forwarding Group dialog displays.
3. Enter a name for the DNS group.
4. Enter the servers (IPv4 or IPv6 addresses) and the domains for the group, and click OK. The custom group displays in the DNS Groups list.
5. Click Save.
When to Enable Recursive DNS
If you have a DNS server that cannot resolve all host names, it might return a list of authoritative DNS servers instead of a DNS A record that contains an IP address. To avoid this situation, configure the ProxySG to recursively query authoritative DNS servers.
To enable recursive DNS:
1. Select the Configuration > Network > DNS > Groups tab.
2. Select Enable DNS Recursion.
3. Click Apply.