Connect via a double NAT setup for remote access to your Raspberry Pi.
Connect via a double NAT setup for remote access to your Raspberry Pi.
As discussed earlier, many people share the same IP address for an extended period, sometimes only for a single day. It’s hard to tell exactly how long someone has been using it. I might adjust my settings later. Typically, most DHCP servers assign a lease duration. If your device isn’t connected when the lease ends, your IP will update automatically. For instance, if my router needs to restart due to an update or Comcast updates its firmware, my IP could shift because the lease expires. Any dynamic IP can change without warning. Static IPs are the only ones that remain constant since they’re assigned directly. You’ll need to configure your router accordingly. But honestly, no IP completely solves this problem. You might install software on a network device, and in some cases, your router can connect directly. They provide an URL, and whenever your IP changes, they update their records.
On another note, when you set up port forwarding for a Raspberry Pi, did you give it a static private IP? Also worth mentioning is that your local network also distributes IP addresses to devices. These are private and can’t be used online. The router serves as a gateway, directing traffic between your devices and the internet. When configuring port forwarding, usually you need a fixed IP or reserve the address from DHCP. Either way, the assigned IP must stay consistent; otherwise, your setup won’t function properly. Just like your ISP’s DHCP server has a limited lease time, so does your router’s allocation.
I just reviewed my router configuration and it’s configured to get a dynamic IP from my ISP, along with the assigned IP. What’s notable is that the IP address coming through differs from what I’m displaying publicly—it begins with 100 on the router side.
You need to verify the WAN IP in your router configurations. This is important since your current IP can't detect CGNAT. Essentially, you must have an internet-accessible IP address. With CGNAT, you're assigning a single public IP to multiple customers, which happens because we've exhausted IPv4 addresses. IPv6 has been available for years, but many ISPs still prefer the older format.
Each router is unique. It’s hard to assist you in this case. However, if you compare the WAN address with the Wikipedia page, check the reserved addresses table.