Fortinet Version 3.0 Normal mode operation, How the FortiBridge unit monitors the FortiGate unit

FortiBridge operating principles Normal mode operation

1Connect the FortiBridge-1000 INT 2 interface to the FortiGate internal interface.

2Connect the FortiGate external interface to the FortiBridge-1000 EXT 2 interface.

3Connect the internal network to the FortiBridge-1000 INT 1 interface.

4Connect the FortiBridge-1000 EXT 1 interface to the router.

Connecting the FortiBridge-1000F (fiber gigabit ethernet)

The FortiBridge-1000F unit contains 4 multimode fiber optic gigabit interfaces that connect to the internal and external networks and to the FortiGate interfaces that were connected to these networks. Use the following steps to connect a FortiBridge-1000F unit to the network as shown in Figure 3.

1Connect the FortiBridge-1000F INT 2 interface to the FortiGate internal interface.

2Connect the FortiGate external interface to the FortiBridge-1000F EXT 2 interface.

3Connect the internal network to the FortiBridge-1000F INT 1 interface.

4Connect the FortiBridge-1000F EXT 1 interface to the router.

Normal mode operation

If the FortiGate unit is operating normally, the FortiBridge unit operates in Normal mode. Traffic from the internal network enters the FortiBridge INT 1 interface then exits the INT 2 interface to the FortiGate unit. The traffic from the FortiBridge INT 2 interface enters the FortiGate internal interface. Firewall policies and protection profiles are applied to the traffic by the FortiGate unit. Accepted traffic then exits the FortiGate External interface and enters the FortiBridge EXT 2 interface. The traffic then exits the FortiBridge EXT 1 interface and goes to the external network. Traffic from the external network reverses this sequence.

Figure 4: Normal mode traffic flow

(Normal mode)

Internal network INT 1

INT 2

Internal

EXT 1	Internet
EXT 2	Router
External

(Transparent mode)

How the FortiBridge unit monitors the FortiGate unit

To monitor the FortiGate unit for failure, you must enable probes on the FortiBridge unit. When you enable a probe, the FortiBridge unit sends packets from the FortiBridge INT 2 interface, through the FortiGate unit to the FortiBridge EXT 2 interface. If the EXT 2 interface receives the probe packets, the FortiGate unit is operating normally. If the EXT 2 interface does not receive probe packets the FortiBridge unit assumes that the FortiGate unit has failed.

FortiBridge Version 3.0 Administration Guide	11
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