Strange behaviour - WiFi vs Ethernet clients

[guest32058]

Hi,

Very new to OPNSense and firewalls in general. Hoping someone can offer their opinion as I'm really confused. If I'm missing anything please let me know.

Legend:

• Modem/router/WAP = ROUTER1
• OPNsense firewall = FW1
• Test PC 1 = PC1
• Test PC 2 = PC2

Version:  OPNsense 22.1-amd64

Setup: From my wall socket is connected ROUTER1. Connected directly into the  LAN ports on that are FW1 and PC1, and PC2 is connected via WiFi. I only  have the LAN port enabled on FW1 right now for config and testing.

Issue:  After disabling the DHCP server on ROUTER1 and re-enabling the DHCPv4  service on FW1 I refreshed the IP on PC1 and everything looked fine- my  Ethernet interface received all of the correct settings from FW1. I sent  a ping to 8.8.8.8 which was successful. I then tried to ping google.com but was not able to resolve the name. After confirming the settings on  FW1 were correct I tested PC2 to find it working as expected. The only difference being PC2 is a wireless client and not plugged directly into ROUTER1.

I am not able to ping FW1  (LAN) from PC1, but I can from PC2. I tried plugging PC1 directly into  FW1, but still ping times out. I'm certain I was able to ping FW1 from PC1 at some stage but I can't say for sure. It's usually the first thing  I'll do when plugging something new into my LAN.

I've tried going through the settings to make sure I've not enabled/disabled something weird, but I can't find anything. The only config changes I've made are very standard- DNS forward added, DHCPv4 client settings,  and ACME client for Let's Encrypt.

Does anyone have any idea what's going on?