12-25-2023 07:55 AM
I am trying to setup DDNS for my synology NAS.
The issue is I am not sure which public op to use. The WAN IP is definitely not private but whatsmyip shows different public ip than WAN IP from router’s setting.
when I access use WAN IP for DDNS, I can access NAS from inside the network but not from outside. Although the public ip reported by whatsmyip does not work at all.
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12-28-2023 06:23 AM - edited 12-28-2023 06:25 AM
Hi, thanks for the reply. I did look for the double NAT earlier but that was not the case and I was at least familiar with the concept.
After a little bit of research, It turned out that, it was a CGNAT turned on by the the ISP. I was not aware of the concept of the CGNAT. However once I reached out to the provider to remove the CGNAT, all started working fine.
Also while exploring all this, I learned about your other suggestion of not exposing the NAS to the Internet. Yesterday I configured OpenVPN with some tight firewall rules and it's working like a charm.
Thanks, again!
12-28-2023 03:35 AM
You might have what's known as double NAT; two inner networks, where the WAN IP obtained by Nest Wifi isn't your public IP, but a local IP, RFC 1918, received from your modem/router combo.
That said: It's not best practice to expose a NAS directly on the internet, consider other options like VPN or Synology QuickConnect (if you got a Synology NAS).
About Synology QuickConnect:
About hosting a VPN server on a Synology NAS:
12-28-2023 06:23 AM - edited 12-28-2023 06:25 AM
Hi, thanks for the reply. I did look for the double NAT earlier but that was not the case and I was at least familiar with the concept.
After a little bit of research, It turned out that, it was a CGNAT turned on by the the ISP. I was not aware of the concept of the CGNAT. However once I reached out to the provider to remove the CGNAT, all started working fine.
Also while exploring all this, I learned about your other suggestion of not exposing the NAS to the Internet. Yesterday I configured OpenVPN with some tight firewall rules and it's working like a charm.
Thanks, again!
12-28-2023 06:26 AM
Ah, CGNAT, forgot about that being an option.
Good to hear you're all set. 👍