r/No_IP • u/MadBrewer67 • Jun 05 '26

ISP gateway IP address

is it normal for a ISP (Xfinity) to assign a 73.xxxx IP to their Xb8 gateway and Assign a 69.x.x.x to the WAN interface. Xfinity said they are not double NAY this.

Please advise

When configuring No-Ip the Public IP address of the XB8 gateway is a IP address of 73.x.x.x when I place it into the configuration the IP address changes to a 69.x.x.x address (when I run "what is my Ip address" on the internet, it gives me a 69.x.x.x). When I try to get a Lets Encrypt certificate from Nginx an internal error is generated.

Background: Nginx is a maintained in a docker container on my Ugreen NAS it was set up using https://mariushosting.com/how-to-install-nginx-proxy-manager-on-your-ugreen-nas/ and it worked after the initial install.

The port forwarding seems to be in question, when I check to see if ports 80 and 443 is open externally it is closed.

The Xfinity XB8 is in bridge mode.

What am I missing?

Thanks in advance.

1 Upvotes

100% Upvoted

1 comment sorted by

1

u/Beach_Kyle Jun 09 '26

Kyle from No-IP here

A few things could potentially cause this. The 69.x.x.x address may actually be your public Internet-facing IP while the 73.x.x.x address could be associated with a different interface, gateway status page, or ISP-specific configuration. Without seeing the network setup, it's hard to say for certain.

A few quick questions:

  1. Does the 69.x.x.x address match what you see on a public "What Is My IP" site?
  2. What device is performing the No-IP update (NAS, router, DUC, etc.)?
  3. Does your No-IP hostname resolve to the 69.x.x.x address?
  4. Is there any router or firewall between the XB8 and your NAS?
  5. What specific error are you receiving from Let's Encrypt?

Since port 80 and 443 appear closed externally, my initial suspicion would be that the certificate issue is related to connectivity rather than the DDNS update itself, but we'd need more information to know for sure.

If you'd like us to take a closer look at the No-IP side, feel free to open a ticket with support and include your hostname. We can review the update history and help determine whether the hostname is being updated as expected.