How do I know if my account is on Dynamic IP or CGNAT?

[vpsj]

I'm noticing that my ports aren't getting forwarded suddenly.

I looked at the Wan IP address on my ONT and it's in the form of 100.176.xxx.xxx . Previously it used to be 176.xxx.xxx.xxx

This seems like it's on CGNAT right? But I placed a service request and both Airtel support on Twitter and the engineer who called me are insisting that my connection is on Dynamic IP.

Is there a specific, non-ambigous test I can run to confirm this other than port forwarding?

Are there any tools or website that can tell me if I'm behind a CGNAT?

I want to be able to demonstrate/prove to the Airtel engineer of my connection's status because otherwise they won't take me seriously.

If you have any suggestions, please let me know.

Thanks!

 

[Rajneesh Rana]

If your IP starts with 100.X.X.X then copy and paste it in any online lookup tool to see if it says private range or public.
Airtel is right - you are still on dynamic IP -> the public IP will be dynamic but you are behind CGNAT.

If possible try using any torrent or other application which uses UpnP connection, if it's not able to open a port for forwarding it should answer your question of being behind CGNAT or having a public IP for your connection.

Also, for users not paying for static IP, they are probably behind CGNAT on Airtel.

 

[vpsj]

Can you recommend a lookup tool to check if it's a private range or public?

And qbitorrent does seem to be able to download fine, the problem is the Plex server that can't connect to my NAS so I can't watch my content if I'm not at home.

If my connection is indeed on a Dynamic IP, what should I tell the Airtel engineer to do? I don't want to pay an extra Rs 300 just to get a static IP.

What options do I have?

 

[Rajneesh Rana]

You can check on ip-api.com
I am also using Airtel and have CGNAT
IP on ONT is 100.90.202.31 which when checked IP-API.com - Geolocation API shows as private range.
However if I check IP-API.com - Geolocation API directly it shows my public IP in 223.177.X.X range.

If you don't want to pay for static IP then you can check tailscale for connection between your machine/phone and NAS.

 

[vpsj]

I checked my IP 100.176.153.xxx and it shows to be an address in Washington, North America lol

 

[JB701]

They really shouldn't be giving that IP out for CGNAT, must be some config error because 100.64.0.0/10 is 100.64.0.0–100.127.255.255

My guess is they put 100.64.0.0/8 prefix instead of 100.64.0.0/10

You are still behind CGNAT, your real public IP can be found on ifconfig.co. No one else can access 100.176.153.xx and connect to your network since there is no route.

See: Reserved IP addresses - Wikipedia

 

[vpsj]

My public address from your link seems to be 106.222.213.xxx and it does show the right city.

Still trying to figure out how to prove to Airtel that I'm on CGNAT (or there is a config error) and to put me on a public/Dynamic IP so my ports get forwarded

 

[Rajneesh Rana]

Airtel won't do anything as the config for you is correct and as per current Ipv4 NAT practices from ISPs.

you can either opt for static IP or try Tailscale or similar application for your usecase.

 

[vpsj]

Problem with tailscale is it needs to be installed on EVERY device that has to use my Plex server, and a lot of my relatives, family members, friends etc who watch content from my server are neither that tech savvy nor will they bother with it.

I am currently using a cloudflare tunnel and it's working but the connection speeds are not as great and there is sometimes some buffering

Question: Do you think I can enable Ipv6 on my router and connect my NAS to the internet that way? As far as I know port forwarding isn't even needed on IPv6, right?

I see the option in my ONT's router settings, not sure what the configuration would be but if it can be a viable solution it might be worth trying?

 

[Dr.Rishi]

Its very simple

Go to the "Check My IP" website and copy your IPv4 address.


2. Paste the copied IPv4 address into your browser's address bar. This will open your ISP router's gateway page.


3. 2nd method


4. Log in to the router's gateway page and go to the WAN section.


5. Compare the IPv4 address shown in the WAN section with the one from the "Check My IP" website.


6. If both addresses are the same, then your connection is not behind CGNAT.