New FTTP - Odd issues with provider NAT

[Callahan]

Hi,

I recently moved away from a FTTC connection to a FTTP connection. This has meant that my OPNSense WAN connection has now changed. It looks like this is now a NATed address as the interface IP is now on a 172.16.11.X address. The address that I actully have from an outside perspective is an expected Internet routeable IP. 2 issues have arisen from this new setup.

1. I'm interested, from a technical perspective, how this is working as I'm struggling to make the routing config they have in place make sense in my head. They are NATing and external IP behind an internal IP. I guess that makes sense, just never thought about it being done in reverse I guess.

2. More importantly, my Dynamic DNS setup on the firewall is, while technically working, and reporting my Internet routable IP as the IP to report into my Dynamic DNS provider (no-ip), devices on the outside of my network can't reach them. This, I suspect is because I use the WAN interface IP in the FW rule and the WAN interface IP is this 172 address.

This has essentially cut off all access to my internal web services. I'm not sure how I can resolve this. I've removed the default option to block private networks on my WAN interface as essentially all traffic inbound from the supplier provided modem will be coming from and RFC1918 address but this, I suspect is only half the solution.

Sure this must be a common problem so if anyone can share any pointers, I'd appreciate it.

Thanks.

[Callahan]

Scratch this post. This looks like a dynDNS client issue on OPNSense that has lead me down the wrong path. Going to abandon it as it never worked properly after they stopped running the old client that was rock solid from day one! Will go back to the no-ip client on one of my web servers.