topic Three Zyxel NR510E 5G router, DDNS and NAT port forwarding stopped working. in Broadband

Three Zyxel NR510E 5G router, DDNS and NAT port forwarding stopped working.

Dave_P — Sun, 25 Feb 2024 10:59:16 GMT

Just over a week ago, my 5G broadband dropped out, on investigating the router, I found flashing lights as if it were restarting itself, so I left it to stabilize.This looks like a silent firmware update to me.

Firmware Version: V1.00(ACBJ.0)b15

After that I could no longer access any of my servers remotely via my ddns domain name ( I have a noip account), or in fact directly using the IPv4 address I obtained from "whatismyip.com". The ip on the router was showing as 192.168.0.2 (I changed the router LAN ip to 192.168.0.1 with LAN ddns range 192.168.0.2 - 254 netmask 255.255.2554.0 to fit in with my existing network). I now have warnings logged that 192.168.0.2 is a problem with the netmask of 255.255.255.255 ???

That particular issue was solved by starting the LAN ddns range at 192.168.0.3.

Under NAT, the port forwarding page would not allow me to change any of my existing rules, I was able to add new rules but only as long as I didn't use an internal or external port number that wasn't being used in any other existing rule regardless of the assigned internal ip (i.e. if I try to make a second rule using internal port 80 from a second IP, the changes are rejected).

Finally, using ssh to look at the external ddns settings using the "cfg ddns get" command I get the following:

ZySH> cfg ddns get
2024-02-25 09:26:47 cfg<24315>, zcfg_msg.c:235, _msg_recv(), WARNING: EID = 61, select() wait forever, EID = 1, type = 2 with reply, oid = 127848

this keeps repeating like a ping would. The router web interface stops populating information on the home page and I see lots of new admin looking options in the dropdown menu, and the internet connection drops-out until I power cycle the router, when it all returns to the new normal (with broken ddns or NAT).

Re: Three Zyxel NR510E 5G router, DDNS and NAT port forwarding stopped working.

andyvee — Mon, 26 Feb 2024 17:23:41 GMT

Try changing the APN to manual settings of 3internet and only IPv4 enabled.

Re: Three Zyxel NR510E 5G router, DDNS and NAT port forwarding stopped working.

Spud — Wed, 28 Feb 2024 11:08:01 GMT

Mucking about with my NR5103E yesterday I also noticed it had a WAN address of 192.168.1.2 (LAN is default 192.168.1.* with DHCP server allocating from 192.168.1.3). I concluded that this is a dummy address due to IPv4 being phased out as it all seemed to connect fine when I set the router to IPv6-only rather than dual stack. I noticed a month or so ago that my 4G router got a IPv6 address and WAN IPv4 was 192.0.0.2 which is a reserved address for Dual-Stack lite https://en.wikipedia.org/wiki/Reserved_IP_addresses

Until the IPv6 transition stabilises I think the sort of issues you report will keep popping up.

Re: Three Zyxel NR510E 5G router, DDNS and NAT port forwarding stopped working.

Dave_P — Thu, 29 Feb 2024 10:33:05 GMT

Hi and thanks for your suggestion,

I did the APN settings thing as you suggested, The external IP address indicated by the router changed to be in the range of the Three allocation.

This allowed me to then access the router externally via it's IP address but only to the server using both internal and external port 80 in it's port forwarding rule, all others are still inaccessible externally.

The Port Forwarding settings still give and error when I attempt to assign internal port 80 on different servers (with unique internal IP addresses) to unique external ports.

I have yet SSH into the router to test the DDNS config with the "cfg ddns get" command, to see if that messes up the router operation.

Re: Three Zyxel NR510E 5G router, DDNS and NAT port forwarding stopped working.

planetmurf — Sat, 27 Apr 2024 23:12:29 GMT

Managed to get mine working tonight after struggling for many hours, I was switching the APN as per the other posts but this broke my internal access to the internet, however I now have managed to get it working.

I changed the following Settings:

Network Setting -> Cellular APN

1 Manual, APN 3internet, PDP ivp4

Network Setting -> Broadband

Celluar WAN1, WAN2 and ETHWAN to ipv4 only and NAT switch on

Network Setting -> NAT

Added port forwards for my services, example homeassistant port 8123 and point it to my home-assisant device IP

Re: Three Zyxel NR510E 5G router, DDNS and NAT port forwarding stopped working.

snoopy — Sat, 25 May 2024 13:00:05 GMT

This is exactly solution that helped me! Especially this line, but all the points are important:

Network Setting -> NAT

Not sure I got confused and was setting up Security -> Firewall -> Protocol & Access Control - for some reason thinking it's a place where I need to put my port forwarding rules, lost about a day trying to resolve this issue.

I need more sleep 😴

Re: Three Zyxel NR510E 5G router, DDNS and NAT port forwarding stopped working.

seventh — Sat, 10 Aug 2024 00:38:54 GMT

I still have no ability to port forward even if i make all the changes to match @planetmurf post above, they get listed as active but seem to do nothing and report closed. Three CS said they made some changes their side which i assume was setting their end to IPV4 only too but no improvement.

Re: Three Zyxel NR510E 5G router, DDNS and NAT port forwarding stopped working.

xhafa — Wed, 20 Nov 2024 15:04:03 GMT

Yep I did the same and this worked for me for CCTV portforwarding

Re: Three Zyxel NR510E 5G router, DDNS and NAT port forwarding stopped working.

Simulacra — Thu, 06 Mar 2025 15:13:25 GMT

Saved my bacon, thanks!