Messages

I have an out-of-the-box OPNsense installation (24.7.3_1) virtualized in Proxmox and sitting behind an ISP router with its own NAT.

My OPNsense WAN IP range is in the 10.0.0.0 range (which is what it gets from the ISP router)
My OPNsense LAN IP range is in the 172.16.0.0 range (which is what I've set in my DHCP range)

What I've observed:

• I can ping and resolve DNS from LAN machines connected to the OPNsense host but cannot access webpages through a browser or through curl
• I am able to access the internet from the OPNsense host VM
• The firewall logs show a pass for the requests I'm making from the LAN to the WAN
• MTR from the VM on the LAN interface shows icmp making it out to the internet but 100% loss at the hop between OPNsense WAN and the LAN interface of my ISP router

Since the OPNsense host is able to connect to the internet but the VMs behind the OPNsense LAN are unable to, my suspicion is that the issue lies within OPNsense. Any suggestions as to what I should check?

They're known for having failures in some random places and the only upstream hop that ping can be used on is our most local gateway but there's still several more with potential to fail before it leaves the country.

My ISP blocks ICMP so WAN failover doesn't work with OPNsense's default failover settings. Are there any alternatives to ICMP that can be used to detect when a WAN connection goes down and when it comes back?

I'm looking to use the GPS NTP server feature in OPNSense and I have an available RS232 (serial) port on my Qotom device but I'm not sure where to look to find a GPS receiver that will be compatible and also have a serial port.

Are there any ones that you've used that you know are compatible with OPNsense and have been performing well?