Transparent Mode

[Suh_Ahamed]

Hello Dears,

We have requirements to configure the firewall without changing the IP addresses on the existing infra.

We have a plan to configure the Firewall in Transparent Mode.

1) The customer has a flat network, From the core switch is the gateways three links are connected to the three different gateway routers with the same subnets.

2)We going to place a  firewall between the core switch (3 LAN  ports ) & ( 3 WAN ports )gateway router, So that each link will connect to the Firewall ports. 

3) The Core switch has different static routes pointing to three different gateway routers.

4) in the Transparent Mode corresponding policy needs to be created along with Mgmt IP 

Does any other layer two loopings will occur in this scenario?

Please share your experiences.

[adambomb1219]

Why use transparent mode at all?  This really sounds like an opportunity for a network redesign instead.  Move all layer3 and WAN functions to the FortiGate.

[Suh_Ahamed]

Dear,

Yes, absolutely right, but the customer don’t want to change the IP address.

[adambomb1219]

Why can't you just move that IP address to the FortiGate?  Perform a hot cut from whatever the layer3 device is today to the FortiGate.

[Suh_Ahamed]

Dear,

The challenge that we have here is that three gateway routers are using the same IP address segment and are connected to the L3 switch with physical connections. We can't change any IP address from existing infra.

We want to add a firewall for the security inspection only.

[adambomb1219]

How do you have 3 devices with the same IP?  Different VLANs have the same IP?

[Suh_Ahamed]

Dear,

single router and three routers using same ip address segment.

[adambomb1219]

I'm not following

[Suh_Ahamed]

Dear,

Sorry, a Single LAN Segment and three Gateway routers use the same IP address segment.

[Suh_Ahamed]

Dear

This scenario is possible in Transparent Mode?