External Router Connecting To 5G Router

You can use a VPN. Unfortunately even IPv6 is heavily firewalled and those settings can’t be changed. 

The problems that can be introduced with the double NAT solution make it a bit of a non starter for me. I have seen the same issues years ago so unless you can run your router in AP mode you might still have problems. Since you can't configure the T-Mobile router to do port forwarding to the external interface of the Linksys I don't know that it is going to work very well. You can't enable bridge mode on the T-Mobile router but you can put your router in AP mode and work around the issue. It just seems to add more complications. 

“When there's double NAT on your network, you might run into issues with services that require UPnP (Universal Plug-and-Play) support or manual port forwarding. This would include online gaming on computers or consoles, remote desktop into your computers, connecting to a VPN server, or accessing security camera feeds." (PCWorld)

O

https://www.purevpn.com/blog/double-nat/

JMarsden92 wrote:

Just a helpful set of info for everyone trying to do more with their 5G routers…

I have a newer Linksys router connected by ethernet to my 5g router.

In the connectivity tab of the Linksys go to the internet settings tab.

Make Static

IPV4 address will be the 192.168.12.2…  (Which is 1 more than the 5g router)

subnet 255.255.255.0

default gateway 192.168.12.1

DNS….  It’s up to you… BUT…

I use Google for 1 and 2 and 192.168.12.1 for the 3rd.

google is 8.8.8.8 and 7.7.7.7

With this solution I can access my computers through Chrome Remote Desktop, and my security cameras and doorbell through P2P.

 

 

What router model is it?  Trying to set up a eufy video doorbell.