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Adding a failover Windows DHCP server to an existing VLAN configuration

Hi everyone,


I recently discovered (I must be a newb) that it is possible with two Windows servers to have one be the primary DHCP server and have the second one as a failover in case the primary server goes down so I configured a secondary DC to be the failover DHCP server.  We have multiple VLANs that uses the same DHCP server and the Fortigate is set to relay to the Windows DHCP server.


Now that I added a failover, how do I add the address of that new server to also be a relay on the Fortigate's VLAN Interface configuration page?


As an example (with fake names and IP addresses):

Good old Windows server called: DC1  on IP  currently has DHCP role so the relay for every VLAN configured in the Fortigate points to that server.

New Windows server called: DC2 on IP  has been configured as failover for DC1.  Now if the primary fails, the computers/devices on the different VLANs who would need a IP address need to be able to reach the relay for DC2.


The box that exists on the Fortigate (in Interface, select my VLAN, under DHCP server, Mode: relay, Type: Regular, DHCP Server IP: is set to my primary DHCP server.  Can I add the secondary IP in there, and if so, separated by what, a comma, a slash?


Technical information:  Fortigate 200F running firmware 7.0.12 build 0523, Windows servers 2019 standard (VM) for the primary and 2022 standard (hardware) for the secondary.  We have two more DC on Windows 2019 standard (VMs) as well.


Thank you for any and all help you can provide and have a great weekend everyone.

1 Solution

Yes comma separated IIRC

View solution in original post


Yes comma separated IIRC


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