Nginx not reachable by browsers, but Nextcloud still working

[pi-rat]

Hello,

 

I’m facing yet another strange problem, and I am posting it here as well, because I think it could be OS related.

 

Some details about my server:

 

• Armbian 26.2.1 trixie
• Nginx
• Nextcloud (latest)
• MariaDB
• Letsencrypt (updated 3 weeks ago)

 

 

Until a few days ago, every browser on any of my devices could call the web gui of my server and Nextcloud presented its login page. Then, after the latest OS update, suddenly browsers tell my they can’t connect to the server, but every synching app on any of devices still work perfectly! And I can even access my files on the server by using FolderSync’s¹ internal file browser.

 

It is just the browsers that can’t connect any more, no matter which browser, no matter which device! There is no error message in the appropriate log files, neither in the system log, nor in Nextcloud’s own log, and the message that the browsers present is simply some variation of “I can’t connect to server”. No specific reason, no error code.

 

This is more than strange to me. I would get it if synching apps would have stopped working as well, but that is not the case. Does any one have an explanation for this mystery? If you need more information, just let my know!

 

Many thanks in advance!

 

(¹ Synching app on Android.)

Edited 1 hour ago by pi-rat

[eselarm]

52 minutes ago, pi-rat said:

I can’t connect to server

Here your debugging activity will need to start. There is an awful lot of things unknown, to others on this forum but more important, also to yourself. It could already be that your server (Armbian) has nothing to do with it, but that it is the info in your router (even caching stuff) that has refreshed, simply because you probably restarted, so something was not 'reset proof'. I have seen many of such things myself in my house/home networking and in conjunction with various ISP's (also mobile4G). Which made me use my own (open-source) router instance for example, so I can at least check all what is needed in such case as you have.

 

But it might be simple, you can use wget (do 'man wget' first to see all options) to mimic browser behavior and that should already say something. If docker etc is involved, make sure you understand all (virtual) networking, it can get very complex. I haven't seen potentially disturbing things from Armbian 26.2.1, but I removed/blocked also several things, like no netplan.io, that at least works on Debian Trixie based installs. There have been lots of security related updates in Debian recently, so make sure you log and see changes to packages (edit listchanges.conf)

Edited 57 minutes ago by eselarm