My ISP recently implemented CGNAT in my area. This caused issues with Double NAT on my network. I was told that the solution to the Double NAT was to get a static IP address. After setting up my router with the Static IP Address, the Double NAT goes away, but my Plex Server does not grab the correct external IP address. It is assigning the Static IP address, as opposed to the public IP address, which is different. Is there any way to fix this problem? Up until the CGNAT implementation, my remote access worked like a charm.
You can’t access it directly.
In your situation, just through a relay, which is not the best experience.
Note : It’s important to understand that if you’re connecting via “Relay”, then it means that your app was unable to make a direct connection to your Plex Media Server. A direct connection will always give you the best experience; see below for information
If your public address is not the same address you have in your modem/gateway, it won’t work.
Maybe you can ask for a port forward to your ISP in your public IP, to your internal IP.
but it’s strange, because the 12.167.x.x is public and also the 208.104.
So it’s not clear to me what they are doing, for sure it’s not common configuration we see around.
When they gave you the Static IP address, did they also give you a subnet mask and a gateway to go with it? Or any further instructions?
My assumption is that you would reconfigure your router to use that address/mask/gateway, instead of the previous automatically assigned public address.
There are other ways it can work, but they’re more complicated and less likely to be supported by common consumer routers.
Other ways it can work? You mean by connecting to a VPN and requesting a port forward there…
Otherwise it won’t work, the packet needs to reach the customer edge to be forwarded to his plex server.
And also, CGNAT is to spare IPv4, so why his ISP is using two public IP addresses? That doesn’t make sense…
He got a “static” address from very different IP space. I’m optimistic about that.
I’m also optimistic that it is intended to become his outside/WAN address. That’s why I’d like to know what other information or instructions he received.
ISPs stealing random IP addresses from other people. “Hey, it doesn’t matter, right? It’s behind NAT.” That’s dumb and depressing but common. It was common before CGNAT too but ISPs should know better.
ISPs using their own address space for this, but using the same address ranges for multiple deployments. This makes a lot of sense and has minor advantages. It doesn’t save as many IPv4 addresses worldwide but it still saves a lot.
ISPs using their own address space temporarily while transitioning to CGNAT.
CGNAT is to share IP addresses between customers, so they all have the same public IP address.
Which means that the router with the public address interface is not at the customer edge, it’s inside the ISP.
Basically, you can’t configure port forward in something you don’t manage.
Yes, of course. I don’t understand your comment “hope his ISP has a different idea regarding what CGNAT is”.
My hope & assumption is that the “static” IP address he was given is not behind CGNAT. CGNAT doesn’t have to be all-or-nothing for all customers and IP addresses of an ISP.
My hope is that it can be used as his router’s outside/WAN address, where port forwarding can be controlled.
Let’s see what additional information and instructions were provided.
If none were provided, then we can give some questions for the ISP.
Yeah, he should speak with his ISP.
But according to him, he has a public IP, and another IP in his router/gateway.
The problem I see is that according to him, both are public, and in a CGNAT, that doesn’t make sense to use one public IP address 208.x.x.x, and another public IP address in his router/gateway 12.x.x.x
That is not what CGNAT is all about.
Guys, based upon your comments, I decided to call my ISP back. They claim that my modem is one of their older modems and after I switch it out, it should fix my problem. I’ll switch it out this week and then see if it fixes the problem.
