Hope someone can help. My remote access stopped working a couple of months ago, having previously been working perfectly. I was getting the Double NAT error message. To cut a long story short I googled a lot. Eventually discovered the fault - my ISP, Hyperoptic, have recently implemented CGNAT (Carrier Grade NAT).
I called them to find out my options - basically they said they were hoping to implement IPv6 ‘at some point this year’, and they can offer me a static IP address for an extra £5 per month. From what I’ve read it seems IPv6 will fix this problem, but in the mean time I’m stuck.
So I’ve taken up their kind offer, and they’ve send me my new fixed address. It appears to be in this format (not posting the actual IP, unless it’s required)
Hyperoptic CGNAT IP (the one that Plex and Google’s ‘what’s my IP’ can see) /
My internal static IP (I assume my router’s external address within the larger Hyperoptic network) / a subnet mask
Plex’s auto detection can only see the first IP, not the second or the subnet mask.
I’ve tried the automated bit, but it still shows the same error. I’ve tried adding the IP to the ‘Custom server access URLs’ field in Network settings, but it didn’t seem to do anything.
From what I can work out, I need to define the external IP, but Plex won’t let me do this.
I was in a similar situation my solution was to use a VPN server. I use AirVPN which supports remote port forwarding.
VPN server sits on DD-WRT flashed Netgear R7000. I use policy based routing so only the computer Plex is on and others I want use VPN as its gateway (most devices within the network connect through default gateway straight to ISP). Adding DNAT rules to the firewall forwards ports through the VPN and then I remote forward the ports on the VPN and hey presto Remote Access.
There is a much easier way which only requires running the AirVPN software on your Plex server but this has limitations if you have other equipment which you want to access remotely.
The reason I went through a router is AirVPN has a DDNS service but only if one connection is active if there is more than one it gets confused. I wanted multiple things going through the VPN so I make one connection with the router and then manage other connections through the router.
Thanks for your reply. Not quite what I was looking for though - don’t really want to go down the VPN route unless it’s absolutely the only option. I’ve now got a paid-for static IP and would like to see if it can work.
I have the labels my ISP gave me for each of the addresses - so I have:
IP address
Gateway IP
Subnet mask
So as I understand it, Plex can see the IP address, but I need it to see the gateway address? Can I do anything in Plex or do I need something different from my ISP?
