There are two main benefits to using non-transparency. The first benefit is that it allows you to browse your Virtual Service when the client is on the same subnet. The other advantage is that the LoadMaster does not need to be the default route in a one-armed configuration. Traffic is forced through the LoadMaster on the way out by making the request appear as if it came from the LoadMaster itself (which is why the IP address is hidden).

Transparency is disabled by default in the LoadMaster.

If cookie persistence, content switching or SSL acceleration is employed for a given Virtual Service, the Force L4 option disappears. As mentioned previously, the chief disadvantage is that the source IP address of the client is hidden, although for HTTP and HTTPS offloaded/re-encrypted Virtual Services it is forwarded in a separate HTTP header. Refer to the following Knowledge Base article for further details: How to Add an X-Forwarded-For Header and Configure IIS Logging.

Note: If the client is local to the Virtual Service, transparency is automatically disabled. If using two VLANs and the netmasks of the two VLANs do not differentiate between them, the LoadMaster decides the client is local and disables transparency. This is not only the case with VLANs - it can also happen when using the same networks on multiple interfaces.