Recently purchased the Optus 140gb mobile data package and I'm having issues setting up my Plex server over it. I am purchased a TP Link MR400 which has set up correctly and the uPNP has set up the port correctly and I can use Plex over the local network however I cannot connect to it from an external connection. Plex is telling me that it thinks the issue is due to a Double NAT scenary. I checked my routers IP address against whatismyip.com and they appear to be different. I confirmed with TP Link that there is only 1 NAT on the router so this must be something Optus is doing? I have also tested this on an Optus AC800s mobile router and I get the same issue.
Does anyone know how to remove this or bypass it?
Not many - unless you have a corporate account ~ $$$ or move to a different provider.
So Optus Owned Virgin Mobile provide public Ip's as far as I am aware.
Also Optus owned Vividwireless service - uses Optus 2300Mhz only but provides a public IP.
Another thing to look at is perhaps a VPN to provide an external IP - there is a way around it but thats out of my knowledge unfortunately.
Thanks Paddylee, unfortunately I've just signed up to 12 months with Optus so I'm committed to them (apparentrly there's no cool off period?)
I'm hoping that setting the router's IP address in DMZ or using IPv6 tunneling might help.
I realise this post is ancient but I do have a solution, its not free but after having the same problem as you, i have solved it.
I use a VPN called windscribe, I have no affiliation with them other than this.
You also need purchase a static IP.
If you connect to the VPN, set up a rule to open a port usually 32400, you can access the plex server over a 4g connection.
This isnt using the plex relay but it shows as being fully accessible outside my network.