Transparent modes (TTP and TI)

In True Transparent Proxy (TTP) Mode and Transparent Inspection (TI) Mode, traffic flows from the client to FortiWeb's bridge interface (without changing the destination IP address), where it is inspected before being forwarded to the backend web server, which responds directly to the client using its original IP address.

Feature	True Transparent Proxy (TTP)	Transparent Inspection (TI)
Traffic Inspection	Inspects traffic based on security policy	Inspects traffic based on security policy, but with limited security features.
Traffic Modification	Can modify traffic (e.g., header insertion, error pages)	Does not modify traffic
HTTPS Handling	Decrypts and re-encrypts HTTPS	Can decrypt HTTPS but does not re-encrypt
SSL Offloading	No	No
TLS Support	Fully supports TLS ciphers, including TLS 1.0/1.1/1.2/1.3.	Supports TLS 1.0/1.1/1.2, but not TLS 1.3
User Authentication	Supports user authentication.	Does not support authentication
Layer 2 Bridge Mode	Yes	Yes
MAC-Based Forwarding	Yes	Yes

When to Use Each Mode:

• Use TTP when you need full HTTPS inspection, traffic modification, and advanced security features.

• Use TI when you only need passive traffic inspection without modifying the packets, especially when TLS 1.3 is not required.