WAN out connection Issues

[Tetra]

I've ran into an issue setting up my personal physical network. I currently can't ping my ISP Router from my endpoint but I can ping the Opnsense WAN from the same endpoint. I believe it might be a routing issue between the WAN and ISP but I'm hopping someone could provide more input. The following is my topology for clarity:

Endpoint --> SVI --> Switch Routed interface --> Opnsense LAN --> Opnsense WAN --X--> ISP Router --> Modem

[viragomann]

Is the OPNsense WAN IP private or public?
Is the ISP routers IP private?
Can you ping the ISP router from OPNsense?

[Tetra]

The WAN IP is private and the IP on the ISP is private that I am trying to ping. I have also tried to ping the ISP's public IP but as expected no luck. I have tried to ping the ISP router from OPNsense with no luck.

[viragomann]

Does the ISP router even allow any access?
What if you connect a computer to it directly?

Do you have internet access through the router?

[Tetra]

So on the ISP I still have some of my other personal devices connected and they can ping each other and the ISP Router, but can't ping still the OPNsense WAN interface. I've confirmed that its properly pulling a IP from the router by restarting the interface. All my other devices work just fine connected the ISP router but this OPNsense WAN interface.

[Tetra]

Follow-up: For testing purposes I did some allow any firewall changes and I believe the firewall was blocking the pings from the other devices connected to my ISP router. The OPNsense WAN interface can now ping the ISP Router private not public, while other devices connected to the ISP can ping the public IP. Other devices can also ping the OPNsense WAN interface but the issue still persists where the endpoint can't ping the ISP Router(public or private).

[viragomann]

OPNsense blocks private networks on WAN by default. Also response packets to incoming access on WAN are directed to the upstream gateway (ISP router) by default.

If you want to access OPNsense from WAN or devices behind it, you have to

• remove the "Block private networks" check in the WAN interface settings,
• check "Disable reply-to" in Firewall: Settings: Advanced,
• add proper firewall rules to the WAN interface.

If you cannot ping the routers public IP from OPNsense, but other devices can, there might be still something wrong.
So we need some more details of your setup.

Is OPNsense running virtualized?

Did it get an IP from the routers DHCP?
Check Interfaces: Overview. Does the WAN show a gateway and the default router?

Also check the gateway status in System: Gateways: Configuration. Is the WAN gateway shown up as online?