Nextcloud Web Lan Wlan connection issues

Support intro

Sorry to hear you’re facing problems :slightly_frowning_face:

help.nextcloud.com is for home/non-enterprise users. If you’re running a business, paid support can be accessed via portal.nextcloud.com where we can ensure your business keeps running smoothly.

In order to help you as quickly as possible, before clicking Create Topic please provide as much of the below as you can. Feel free to use a pastebin service for logs, otherwise either indent short log examples with four spaces:

example

Or for longer, use three backticks above and below the code snippet:

longer
example
here

Some or all of the below information will be requested if it isn’t supplied; for fastest response please provide as much as you can :heart:

Nextcloud version: 25.0.3.2
Operating system and version: Ubuntu 22.04.1 LTS, Proxmox, NextcloudVM
Apache version: 2.4.52 (Ubuntu)
PHP version: 8.1

Hi,
My Nextcloud instance is running on a VM in proxmox behind a reverse proxy (and let’s encrypt certificate). All worked fine with connection from web and locally. Now i face the issue, that I can no more connect to Nextcloud over LAN from one specific computer (using URL). If I change to WLAN connection there are no issues. My laptop over WLAN works as well. Android Version working as well.

Steps i took but the problem remains on this specific PC (only on LAN):

  1. deactivated firewalls
  2. tried with other browsers
  3. changed IP and Computer name
  4. deactivated IPV6
  5. deleted the bruteforce list in mysql on Nextcloud → clean
  6. checked IP tables on Nextcloud and Proxyserver → no bans

I can not pinpoint the source of this strange issue… May be someone of you guys has an idea.

many THX

Compare C:\Windows\System32\drivers\etc\hosts on the PC with the issue and the working PC. Maybe there is a manual but wrong entry in the file.

Annother problem might be caused, if you use a 3rd-party anti-virus software.

thanks for your effort and reply! I thought about that and checked again but both hosts files show the same entry. I think this is not the issue because over WLAN connection on the “issue” PC I can reach the Nextcloud server via URL… I use windows defender on both machines.

127.0.0.1 view-localhost # view localhost server

having too little informations to judge just an educated guess - given the fact WLAN and LAN are more or less the same network, just different IPs for same device (-> really?), the problem must be related to the IP you are using in WLAN. maybe you triggered brute force protection somehow (testing yourself, bad app etc…). try another IP in WLAN and check if the problem persist… you already check basic bruteforce things… what is the difference in your LAN vs WLAN? same system? same IP range? DNS and routing?

And this is the address you use to connect?

When you can’t connect, can you still ping it?

Thx for all the support and ideas.

The problem still remains. I tried different config.php configurations of the nextcloud instance. If i deactivate forced https (it is behind a reverse proxy) i can without problems connect via the internal IP. External URL from LAN connections are not working. WLAN connections with direct IP (no ssl-certificate) and external URL (with ssl-certificate due to proxy) are working without problems. I even tried a Rasperry pi, the same problem remains. And yes, the internal IPs on LAN/WLAN are in the same range (DHCP, 192.168.0.1-254). I tried another install of nginx reverse proxy and the problems still persists. Restarted my modem/router etc.

I think the problem lies within the modem/router of my internet provider and the silent updates with some strange NAT/loopback/hairpinning rules or maybe firewall or header problems… But i do not get why only the LAN connections are affected and how to test this. There are some guys from the Cablecom/Sunrise community who have reported the same problem (see the link).

For me, I am out of ideas. My Internet provider does not care and “just rebooted the modem…!” Maybe a new Nextcloud install can resolve the problems (i have not triedyet) but i highly doubt that. For now i entered the local IP for nextcloud on my working PC (LAN) as a quick fix… But it is kind of frustrating.