Internal1 mac address creating IP Conflict

[bainwave]

Hello All, Got Fortigate 80C unit. All of a sudden, my internal 1 port started sending ip conflict to the machines in my network. This i found in the affected machines event viewer. The event viewer throwing a message stating that this ip is used by a machine with xx xx xx xx xx mac address. That mac address belongs to internal 1 port of fortinet firewall. The following were tried on the affected machine.... 1. Removed and re installed the LAN drivers twice 2. Changed the ports and cables as well.. 3. Finally formatted the machine and re installed the OS and drivers Despite of working for the last 2 days we did not able resolve the issue. I have servers in production. Your advise in highly appreciable. Thanks in advance.

[bainwave]

Am attaching my network diagram image. Location B users using web proxy in fortigate and accessing internet from location A. Waiting for your replies.

[ede_pfau]

You' ve got the same subnet on both sides of a routed link, really? How is that going to work?

[bainwave]

10.44.71.1/25 (255.255.255.128) (location b) traffic is routed to 10.44.71.129 which is a port configuration in location A l3 switch. and the traffic from location will be routed to 10.44.71.1/25 (location b)

[ede_pfau]

Ah, OK, each is one half of a Class C subnet. That' s OK.

[rwpatterson]

Check the subnet masks on the FGTs themselves. One may be a class C (/24) instead of a /25.