Intermittent network connectivity issues on Ubuntu 20.04 with NetworkManager and custom DNS settings
I've spent hours debugging this and I'm building a feature where I've searched everywhere and can't find a clear answer... I am experiencing intermittent network connectivity issues on my Ubuntu 20.04 desktop that seems to be related to custom DNS settings configured through NetworkManager. I've set my DNS servers in the `/etc/NetworkManager/NetworkManager.conf` file as follows: ```ini [main] dns=none ``` And in my connection settings, I manually specified the DNS servers under the IPv4 settings: ```plaintext DNS: 1.1.1.1, 8.8.8.8 ``` However, sometimes the system fails to resolve domain names, and I see this behavior when trying to ping a website: ```plaintext ping: www.example.com: Name or service not known ``` I’ve tried restarting the NetworkManager service with `sudo systemctl restart NetworkManager`, and while it temporarily resolves the scenario, it reoccurs after some time. I also checked the logs using `journalctl -u NetworkManager` and found messages like: ```plaintext [NetworkManager] <info> [1673249583.1234] dnsmasq: failed to create listening socket for address 0.0.0.0:53: Address already in use ``` Interestingly, I don't have any other DNS services running, and the only other network configuration I use is a static IP set through the graphical user interface. I have looked into disabling the `dnsmasq` caching service but that doesn't seem to help either. Has anyone else faced similar issues, or does anyone have suggestions on how to properly configure DNS settings in this scenario to avoid these drops in connectivity? For context: I'm using Plaintext on Ubuntu. Any ideas what could be causing this? For reference, this is a production microservice. I'm using Plaintext LTS in this project.