Fortinet 5.0 Patch 6 - page 69

Fortinet 69 FortiWeb 5.0 Patch 6 Administration Guide
Figure 13:Example network topology: reverse proxy mode with HA
If FortiWeb will not be operating in reverse proxy mode (such as for either true transparent
proxy mode or transparent inspection mode), typically you would not use FortiWeb HA — this
could require changes to your network scheme, which defeats one of the key benefits of the
transparent modes: it requires no IP changes. Instead, most customers use an existing
external load balancer/HA solution in conjunction with FortiWeb configuration synchronization
to preserve an existing active-active or active-passive topology, as shown in Figure 14.
If you use a switch to connect the heartbeat interfaces, they must be reachable by Layer 2
multicast.