Connection to Fortimanager using DHCP WAN IP

[youmustbecrazy]

Hi guys please help,

I have a task in my office to create SD-WAN connection via FortiManager. but I have confused to make connection from Fortigate Branch to FortiManager because the branch WAN is DHCP with private IP. the position of FortiManager is on server (behind NAT) and it has public IP by using NAT from Fortigate. 
Is there any KB or suggestion to establish connection between it to make Fortigate on branch can be managed by FMG and create SD-WAN connection? Please advice ....

topology:

                            |HQ Site|                                                                                                                                |Branch Site|

Fortimanager (Public IP NAT) --> coreswitch --> Fortigate (static WAN1) <--> internet/ISP1 <--> Fortigate (DHCP WAN 3) <-- Coreswitch

                                                                                                                |                              X                               |

                                                                                                                |                              X                               |

                                                                                     Fortigatee  (static WAN2) <--> internet/ISP2  <--> Fortigate (static WAN4)

*each fortigate have 2 WAN interface with diferrent IP and will implement redundant links for SD-WAN ,  WAN1_HO <--> WAN4_Branch ,  WAN1_HO <--> WAN4_Branch,, and vice versa

FortiGate FortiManager  #SDWAN #tunnel #ipsec

FortiGate FortiManager 

[gfleming · Accepted solution]

Here's some documentation helpful to your case:

https://docs.fortinet.com/document/fortimanager/7.2.1/administration-guide/522489/configuring-the-ma...

Basically the FGT will know the FMG public NAT IP address and will initiate connection to the public IP address. Does not matter if FGT IP changes, it will update FMG anyway.