Fortigate 60D (FortiOS v6.0.5) - DHCP Conflict IP in Interface1

Forum|Forum|6 years ago
January 2, 2020
3 replies
5188 views

Hello, when trying to save any changes to the Interface1 screen, the DHCP server Starting IP reports Conflict IP and could not find this IP conflict in the Firewall ARP table. 
My DHCP range is large and even using a windows program called "Advanced-IP-Scanner" to scan the entire network for IPs and DNS I could not find duplicate IP.
See attached file.

Interfaces.png

FortiGate 60D

emnoc

New Member

What's the interface address and subnet. You range has to fix in that network. I believe your error is the range is greater than the interface network.

You can test the error via the cli also.

homefgt (1) # show config system dhcp server edit 1 set dns-service default set default-gateway 192.168.1.99 set netmask 255.255.255.0 set interface "internal" config ip-range edit 1 set start-ip 192.168.1.110 set end-ip 192.168.1.210 next end next end

homefgt (1) # config ip-range

homefgt (ip-range) # edit 1

homefgt (1) # set end-ip 192.168.2.250

homefgt (1) # end start-ip: 192.168.1.110 and end-ip: 192.168.2.250 are not on the same subnet. object check operator error, -40, discard the setting Command fail. Return code -40

that should related to your window UI error.

Ken Felix