NR5103EV2 - CGNAT

Miller2003 — Tue, 01 Apr 2025 17:26:09 GMT

Hi everyone,
Just got off the phone with three support, where I asked why I could not ping my server from outside of the network. I can't connect to any services through opened ports in the firewall, but can through cloudflare tunnels. The three support agent said that three does not support regular NAT. Did this change recently, because my router was working perfectly in November, but stopped working around December time.

I followed the steps here but this didn't resolve the issues, however I did find out that maybe three has enabled GCNAT for me, even though i am on the 3internet APN, as seen below. Other posts I've seen suggested I should set PDP Type to IPv4 only, but when I do this I can not get internet reception at all.

Re: NR5103EV2 - CGNAT

JonathanB — Fri, 04 Apr 2025 13:26:00 GMT

Hi @Miller2003,

Sorry to hear about the trouble this is causing. You shouldn't be picking up CG NAT from 3internet, we only use that type of service for our mobile APN: three.co.uk to my understanding.

I'm not sure why IPv4 only should be failing here, there's some more detailed instructions that community members have sourced on this thread if it helps:

Alternatively, I know the support team are able to configure an IPv4 only APN on their end too, if IPv6 specifically seems to be causing some issues with your devices or set up.

Thanks,
Jonathan

topic Re: NR5103EV2 - CGNAT in Broadband

NR5103EV2 - CGNAT

Re: NR5103EV2 - CGNAT