"One way traffic (reverse). Bypassed because of a network interface setting." displays in the active session statistics


Article ID: 166735


Updated On:


ProxySG Software - SGOS


 When looking at the bypass connections statistics in active sessions, I see many entries of  "One way traffic (reverse). Bypassed because of a network interface setting."


This issue is normally experienced in an WAN optimization deployment, and is typically caused by a  mis-configured network environment where the proxy does not see the SYN from the client.

  • The proxy can only intercept traffic if it sees a complete TCP handshake. If it only sees partial TCP handshake, the proxy bypasses the connection and you see the message above in the bypass connection list.
  • In this scenario, the proxy only sees a SYN-ACK from the fileserver, and it never saw the SYN initiated by the client, therefore the proxy bypassed the traffic.


  • To verify the problem, perform a packet capture on the ProxySG appliance with the client and server filters enabled.
  • Configure your network to make sure that the traffic from the client is routed to the ProxySG appliance.