Nat Strict Teredo IP error

Yes, NAT type shows strict and testing the multiplayer connection yields this error: 'Can't get a Teredo IP address'

@zanswerlive

Yea the IP address is public when I'm connecting ONE directly.

I tried factory reset, still same issue. Teredo IP error and strict NAT, tomorrow I'll contact my ISP because there is nothing left for me to do.

@NikkieMotors

Ok, first I've think about asking You to try to disable firewall, but if You already tried connecting Xbox One to modem and situation was the same, then problem not in Your router.

When connected Your Xbox One to modem directly last time is IP address was like that You copy to me? I mean address was not from private networks like this: 192.168, 172.16., but like now from public?

Such situation can be seen because of two things, first some internal software issue in Xbox One, so it must be reseted to factory defaults and second Your ISP use some sort of filtering on their side. So before trying to reset console, I'll suggest You
to contact Your ISP technical support and ask them about NAT, Firewalling/Filtering on their side and do they have any policy for incoming/outgoing traffic to/from user.

Some ISP's can filter some types of traffic, like GRE tunnels or Teredo tunnels on their side, because this can help to protect users and their network from using users devices as part of botnets and so on.

@zanswerlive

I meant that I done all the things you said but I also tried them before, just mentioned it..

everything as you said

firmware version: 3.13.31 Build 130105 Rel.66489n

I also tried connecting my XONE directly to modem with eternal cable, without any router or PC in between but still same problem.

@NikkieMotors hey hey

Let's set Your configuration to recommended state:

1. Check if Your modem is on bridge mode or not, if not set it to bridge mode.

2. Check that manual port forwarding, DMZ, port triggering and so on is disabled and only UPnP is enabled.

3. Check WAN IP address on Your router and copy first two octets, as example: 172.16.x.x