VPNs Not Working Properly

chikobara · 2025-01-29 05:11:14

Problem Summary
I'm experiencing a strange issue with VPN connections on my Arch Linux (EndeavourOS) laptop when using my home ADSL network.
The VPN connects, but I have no internet access. However, the same VPN setup works fine under certain conditions.

- Android Phone & Windows VM (on the same Linux laptop) connects to VPN over ADSL without issues.
- VPNs on Same Linux Laptop (when using 4G/hotspot instead of ADSL), works perfectly.

What Fails:
- Linux laptop on ADSL: Connects to VPN but has no internet (except for pinging IPs).
- I tried pinging some IPs and realized there is internet access, but not for browsing. I tried downloading some data via Steam as an example, which worked.
- I also tried a telnet to port 80 of YouTube.com and got this output.
- Tried multiple VPN clients (ProtonVPN, RiseupVPN, Windscribe - works only on stealth protocol & UDP).
- System updates via yay, or Steam downloads works, but web browsing does not except Google search webpages sometimes work.

What I Have Tried:
- Manually setting `/etc/resolv.conf`:

# Generated by NetworkManager  
nameserver 1.1.1.1  
nameserver 1.0.0.1  
nameserver 8.8.8.8

- I can ping IP addresses (e.g., `8.8.8.8`).
- Manually setting DNS in `/etc/resolv.conf` does not fix the issue.
- Flushed DNS cache, restarted NetworkManager, tried different resolvers, tried reseting network configurations and reinstalling Networkmanager.

Possible Causes (Need Help Debugging)
- I don't think it's an ISP block or a WiFi router issue right?
- Could this be a Linux-specific networking issue? Possibly, since it works on 4G but not ADSL. But I tried resetting network configurations, reinstalling NetworkManager, and flushing DNS.
- Firewall/routing issue? Could be, but I need guidance on what logs to check.

What Logs & Configs Should I Provide?
I would appreciate any debugging steps and guidance on what logs/configurations to share.

resolv conf when initializing connection

File: /etc/resolv.conf
nameserver 10.2.0.1
search .

ip route

╰─ ip route          
default via 192.168.1.1 dev wlan0 proto dhcp src 192.168.1.3 metric 600 
192.168.1.0/24 dev wlan0 proto kernel scope link src 192.168.1.3 metric 600

inxi -Fxz

ip a

nslookup google.com/example.com

systemd-resolve --status

WireGuard config & Logs

Protonvpn logs