Cannot access Nextcloud server locally via domain and external IP

[NathanielC]

Hello everyone,

I'm encountering an issue with my Nextcloud server setup that I hope someone can help me troubleshoot. Here are the details of my setup and the problem I'm facing:

1. I have successfully set up a Nextcloud server on my home computer running Linux Mint, using a LAMP stack.

2. I registered a domain with Hover and pointed the DNS records to my correct Telus external IP address.

3. In my Telus router (NH20A), under Network > Firewall > Port Forwarding, I configured two port forwarding rules:

   • TCP&UDP forwarding for the internal (server) IP address for private and public ports 80.
   • TCP&UDP forwarding for the internal (server) IP address for private and public ports 443.

   I initially tried setting them to TCP only, but that did not resolve the issue.

4. Despite these configurations, I am unable to access the Nextcloud server using my domain or external IP when connected to my home network. However, I can successfully access the server using "localhost" on any computer connected to my Telus internet.

5. I can access the Nextcloud server on external devices.

6. Restarting the router did not resolve the issue, and Telus support was unable to provide a solution.

I would greatly appreciate any guidance on what I might need to adjust or update to enable access to my Nextcloud server using the domain or external IP within my local network.

Thank you for your assistance!

[Nighthawk · Accepted solution]

You won't be able to access any server on your network from devices on the network using the external IP or domain. It's been that way for many many years and is the way Telus has their overall network configured. I have the same issue on my connection. Tech support has no way to deal with this. I'd wager that most have no idea this issue even exists.

[NathanielC]

Thank you for that prompt and helpful response. Do you have any idea why this is the case or how I can bring this to their attention for correction?

[Nighthawk]

Telus has never said why. Considering it's been in place for more than a decade, I doubt there is any correction that can be made. The restriction from accessing your own external IP from the LAN has always been there as far as I know. Originally people were not allowed to run servers on home connections back in the DSL days. People still did but a number of commonly used ports were blocked for incoming connections so they had to use non-standard ones. With fibre Telus relaxed many of the restrictions and the majority of the blocked ports are no longer blocked but the issue we're experiencing is still there. As far as I can tell the issue is only affecting residential connections.

[FuzzyLogic]

I have managed to get something similar working.

There are a few issues at play. I believe that using port 80 (and likely 443) can be problematic as these ports are blocked for home users.

I have a Synology NAS and I had to use alternate ports to get it to work both internally and externally. Additionally you would either need to set up a internal DNS to complete the process or edit the hosts file on any systems that are internal to make access via the domain name work. I opted for the latter as I didn't wish to complicate my setup and only have a couple of systems that need access.

[NathanielC]

That's a good idea. The only thing that I can do to get it working internally is to use the internal IP at home and the domain when I'm out. It's an a clumsy and ungracious workaround.

[FuzzyLogic]

I didn't like that my SSL certificate didn't work internally until I added the domain to the hosts file. It's an easy fix.

I have an entry of the form:

192.168.1.100     myserver.mydomain.com

This makes is work on the systems where this entry has been setup. If you aren't familiar with the hosts file there is some info here:

hosts (file) - Wikipedia