Allow communication between two IP addresses on different interfaces..?

  • I've installed Pfsense on a PC with three (3) network interfaces, as follows:

    Office router
    PFsense WAN interface
    +-Pfsense LAN_0 interface: (internet is ok)

    +-Computer X (.37)

    +-Pfsense LAN_1 interface: (internet NOT ok)
        +-Computer Y (.101)

    How can I do these two things?

    1. Allow unrestricted communication between Computers X & Y only.
    2. Otherwise, block LAN_1 from all other communication to/from anywhere (isolate it completely).

    From reading other forum posts, I've already set Pfsense as the gateway for both network. But looking at the Firewall & NAT rules, I'm not sure which/what to do.


  • Firewall rules control traffic that ENTERS an interface, so if you want to stop LAN_0 clients from accessing LAN_1, you need to put your rules on LAN_0.  You will need two rules for each interface:  one rule to allow only that specific client to the other client, and then a general block underneath it to handle all other clients.  By default, LAN_) has an ALLow for ANy rule that gives it Internet access.  All subsequent LANs do not get ANY rules, so you must add at least one for any traffic to flow.

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