Nat – pfSense NAT failing – TCP connection built, no traffic

nat;pfsense

I have a pfSense VM configured with two vNIC's that are both connected to the same VLAN. The pfSense has been configured to a static IP. I have a VM with one vNIC that is configured to use a manually assigned address. I have a NAT rule that forwards traffic to port 3389 on the WAN interface IP address to 3389 on my VM. When I try to connect via Remote Desktop it fails, but viewing logs on both ends I can see that the TCP connection was built. What gives?

Best Answer

NAT Port Forwards in pfSense also require a corresponding firewall rule. I would double check your firewall rules, and also determine if the connection is failing at the pfSense instance or on the RDP destination VM by trting to RDP to the VM internally.