Unidirectional Firewall Rule?
I am trying to find a way to create a firewall rule that only allows UDP traffic within a session to flow in one direction (i.e. disallowing any return packets within the session).
I would like to replicate a similar action to a stateless firewall where if I have an allow rule, there isn't a silent secondary rule to allow return traffic within the same session (state).
I am specifically trying to create this for UDP syslog traffic. Since the protocol itself never has return packets within a session, I would like to lock down the firewall rules even more by never allowing bidirectional traffic.
Does anyone know how to create such a rule in pfsense?
I have tried adding advanced options to my rules with states set to none and reply to set to no. I have also tried adding floating rules allowing WAN to LAN UDP syslog, then a rule before it blocking any packets flowing the other direction, but that still failed.