How to check for CGNAT?

Issue

All Firewall and Port forwarding rules are 100% correct, yet nobody can join your home-hosted Server!

If you have connection problems and you are using a Hosting-Service, contact them for assistance. If you want to use a VPS, take a look at this list of Partnered hosting services (Server setup documentation)

How to check for CGNAT?

Method 1:

Open a command prompt, run tracert -4 beammp.com. This will output a series of network hops. Wait for the operation to finish (may take up to 30 hops). Check the first few IP addresses after the IP of your Router/Modem/Gateway. If multiple IP addresses within the range of 100.64.x.x-100.127.x.x or 10.xx.xx.xx appear after the first hop, you are most likely behind a CGNAT. The first hop is your Router/Modem/Gateway and differs between Devices.

Method 2:

Find out the WAN IP on your router by looking it up on its interface. Compare it to the IP posted on e.g. https://whatsmyip.org . If they are NOT the same, you are behind a CGNAT.

Method 3/Solution:

Call your Internet Service Provider for assistance. Depending on your ISP, they might not offer dedicated dynamic IP adresses, or as a paid option only. Keep in mind, that a static IP is not necessary.

Example of a non-CGNAT Network:

Tags: Server, 10060 10061, CGNAT, Connection Failed, Port Forward, Firewall