In 5.0 Fortinet offers the option of using DDNS to register a DNS name if you have a dynamic address. This is great for remote offices who might need a IPSEC site-to-site tunnel to a corporate office. No static IPs! Its very easy to configure and free if you use Fortinets own service. You can configure this under System – Network – DNS.
Notice that this is set to only port15. What if you had two dynamic interfaces from two separate ISPs and wanted to create redundancy for your VPN? From the GUI you cannot. CLI to the rescue! Fortinet has a lot more options for this in CLI. You can create other DDNS interfaces and use more services then just fortiddns. For instance I use dyndns and could actually use my account with dnsalias.com.
Check out these options:
So from here you can select any interface to monitor or use any of those ddns-servers – crazy this is not in the GUI!
One thing to note is that when multiple DDNS entries are created only one shows up in the GUI.