Technical Note: DynDNS VIP

[jrosado_FTNT]

Description
If the WAN link uses a dynamic IP address and a FortiGuard DDNS FQDN has been configured, it may be used to reach internal services by the means of a VIP.
Solution

Make sure an FQDN has been configured for FortiGuard DDNS service.

config system ddns
    edit 1
        set ddns-server FortiGuardDDNS
        set ddns-domain "myfortigate.fortiddns.com"
        set monitor-interface "wan1"
    next
end

Configure a VIP leaving the external IP address all zeros. 

config firewall vip
    edit "PublicServer"
        set extip 0.0.0.0 0.0.0.0
        set extintf "wan1"
        set portforward enable
        set mappedip 192.168.1.250
        set extport 8010
        set mappedport 8010
    next
end

You should be able to reach the server on the FortiGuard DDNS FQDN and port you defined on the VIP.

            http://myfortigate.fortiddns.com:8010