I'm setting up a server with Debian and have been facing a frustrating issue where it disconnects from the network seemingly at random. When I try to ping, I get a "Destination Host Unreachable" message, and the only fix is to run 'doas systemctl restart networking.' I've replaced the network card, turned off Wi-Fi and the built-in Ethernet in BIOS, switched routers, disabled IPv6, and assigned a static IP. I even created a service that pings the router, restarting the network if it fails, but the disconnects keep happening — sometimes hours apart and sometimes every five minutes. This is especially puzzling because this new server uses the same network card and router as my old one; the only changes are the server components and the operating system. I did notice that the disconnects might be more frequent when I SSH into the server, but they happen regardless. I've checked various logs, including the networking service log and kernel logs, but nothing stands out as a specific issue. At this point, I'm starting to suspect it could be a deeper hardware issue. By the way, I just ran a Memtest and it looks like the RAM is totally faulty, which may explain some erratic behavior I had noticed before. Any insights on what could be causing the network issues?
3 Answers
I had this issue once, and it turned out I had multiple tools trying to manage my network at the same time. After setting up a bridge for my interface, everything seemed fine until I noticed my connection kept breaking. I found out that 'connman' was also managing the same interface and failing to get a DHCP address which caused it to revert to a link-local address. Make sure you don’t have conflicting network management tools like connman, NetworkManager, or systemd-networkd fighting for control over your network interfaces. Disabling connman and rebooting solved my problem completely!
Using a UPS could also be beneficial to stabilize your connection. Fluctuations in power can cause network issues too, especially with new hardware. I know it might be off-topic, but it’s worth considering—power stability is crucial for continuous operations!
It sounds like you're dealing with some serious network troubleshooting! Since you mentioned your Ethernet controller is RTL8125, I suggest checking if the r8169 driver is loaded. Run 'lsmod | grep r8169' and if it's there, you might need to blacklist it. Then, you can install the appropriate driver for your card. Update your sources list to include 'main contrib non-free non-free-firmware', run 'sudo apt update', and install the required packages with 'sudo apt install build-essential linux-headers-amd64 dkms'. After this, create a blacklist config file for r8169 and install the r8125 driver using 'sudo apt install r8125-dkms'. This helped me in a similar situation with my Debian setup.
I appreciate the suggestion! I prefer owning my hardware rather than dealing with subscriptions, but keeping everything stable is a good point! Thanks for the tip!