FortiClient proactively defends against advanced attacks. Its tight integration with the Security Fabric enables policy-based automation to contain threats and control outbreaks. FortiClient is compatible with Fabric-Ready partners to further strengthen enterprises’ security posture.
Article Id 249923
Description This article describes why FortiGate blocks reverse packets with a 'drop broadcast: ...' message when in TP mode.
Scope FortiGate.



Packet in original direction flows as: Client >> LAN router >> FortiGate >> ISP router
Packet in reverse direction should flow as: ISP router >> FortiGate >> Client


This happens when the client's MAC address is not in the bridge forwarding table (even if the correct session matches the return packet for TCP sessions).

In TP mode, the FortiGate supports reflection sessions (traffic can back and forth several times), so FortiGate cannot simply just match sessions.


It is possible to select one of these solutions.

1) Add mac address to FortiGate's ARP table

2) Create a reverse direction policy to allow the traffic.