Outbound NAT traffic being lost on return.

  • Hello! I have an odd issue I haven't seen before with pfsense.

    I have pfSense on a VM with two NICs and a relatively default setup. The outbound NAT is on automatic, the WAN's gateway is properly defined, from pfsense I can ping outside hosts and can do DNS lookups.

    When I get on a node on the LAN network, we can do DNS lookups against the pfsense box but can't reach the outside world. When I do a packet capture from pfsense on the WAN side, I only see the initial SYN going out. There is absolutely no traffic flowing back to pfsense. Any ideas?

    This pfSense instance is a VM. Here is a quick diagram of the network on the host system.


  • Do a tcpdump outside the host on the router or connect another computer to the hosts eth0. Possibly the host is blocking the traffic.

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