Technical Tip: Packet fragmentation for chassis based FortiGate

[wdeloraine_FTNT]

Description	This article details the process of fragmented packets on chassis-based FortiGate.
Scope	Chassis-based FortiGate-6000F, 7000E, and 7000F Series.
Solution	Default Configuration: config load-balance setting      config workers          edit 3              next          edit 4              next          end      end The first part of the packet is sent to the correct worker, but all subsequent fragments are broadcast. Enable DP fragment session: config load-balance setting     set dp-fragment-session enable         config workers              edit 3          next              edit 4          next      end  end The behavior remains the same: the first part of the packet is sent to the correct worker, but fragments are broadcast. ISF sw distribution method change: config load-balance setting     set dp-fragment-session enable         set sw-load-distribution-method src-dst-ip             config workers                  edit 3              next                  edit 4              next          end      end The first part of the packet is sent to the correct worker, and all fragments are also sent to the correct worker. Related document: Load balancing TCP and UDP sessions with fragmented packets