Direction in firewall states: CLOSED:SYN_SENT

[blubber7196]

Hi,

Here is my network setup:
pfSense -> switch 1 -> switch 2 (switch 2 is connected to switch 1 which is connected to pfSense doing interVLAN routing).

When I was playing with VLANs, I found myself in situations where I couldn't connect to another VLAN due to VLAN misconfigurations.

For example, in the Users VLAN connected to switch 2, I wanted to print to the Printers VLAN on same switch.

I saw the packets going through pfSense because the firewall created states for this connection.
This is what I saw in Firewall States:

| Interface | Source and destination | State |
| USERS | Workstation_IP:port -> Printer_IP:port | CLOSED:SYN_SENT |
| PRINTERS | Workstation_IP:port -> Printer_IP:port | SYN_SENT:CLOSED |

I found out what the problem was, I had configured the port between Switch 1 and Switch 2 as untagged (access) port for the PRINTERS VLAN, so pfSense was sending the packet with the PRINTERS VLAN ID but Switch 1 was not forwarding it to Switch 2.

What I can't understand is how to interpret those firewall states, I've read the documentation on interpreting states but it doesn't help.

For the state on the USERS interface, why does pfSense put CLOSED on the left side (the source which is obviously the workstation) and SYN on the right side.

For both states, I'd expect to see SYN_SENT on the left because the workstation is sending a SYN packet and CLOSED on the right because the destination is not responding.

Could someone help me understand the logic behind these states?