Technical Tip: Adding multiple DDNS entries

Vichu_94 · ‎08-26-2022

Description

The article describes how to configure multiple DNS entries.

Scope

FortiGate.

Solution

The option to add multiple DDNS entries is configurable only on the CLI of the firewall.

For configuring the Multiple DDNS entries, follow the below command:

config system ddns
edit 1
set ddns-server FortiGuardDDNS
set ddns-domain "test1.fortiguardddns.com"
set use-public-ip enable
set monitor-interface "port1"
next
edit 2
set ddns-server FortiGuardDDNS
set ddns-domain "test1.fortiguardddns.com"
set use-public-ip enable
set monitor-interface "port1"
next
end

Each unit has a limit to the number DDNS entries which could be configured on the firewall.

To verify that, follow the below link:
Maximum Values Table

In the table, check the entry system.ddns:ddns-server-ip to verify the number entries could be added to the firewall.

From version v7.4.0, DDNS can be configured in GUI as well. A few things need to be kept in mind: the number of DDNS entries that can be configured is restricted by table size. For entry-level FortiGate models limit is 16, the Mid-range is 32, and the high-range is 64, respectively.

There is no license requirement for DDNS service, but configuring DDNS in the GUI is not supported if:

The FortiGate model is a 1000-series or higher.
The FortiGate is a VM.
The DNS server is not using FortiGuard as the DNS.

GUI:

Important Note:

After upgrading to v7.4.0 or later, any already configured DDNS entries exceeding the limit for the FortiGate model will be deleted. For example, if a user has 20 DDNS entries before upgrading to v7.4.0 and uses an entry-level FortiGate, the last four DDNS entries will be deleted after upgrading.