#Fedora
VM Has an IP But No Internet: The Culprit Is Docker
My virtual machine picked up an IP address over DHCP and could reach the host, but it could not reach the internet. Network settings, driver, NAT mode; everything was correct. The cause turned out to be a Docker firewall rule. Anyone running KVM/libvirt and virt-manager on the same machine can hit this. I tried the fix everyone recommends online — restarting the virtual network — and it did nothing. The packet counters gave the real answer: Docker's policy drop in the FORWARD chain was discarding my VM's packets before they ever reached NAT. Here is the diagnosis step by step, and a permanent fix with a systemd service.
Why Is My WiFi Slow on Fedora? The Culprit Is Bluetooth (Intel CNVi Antenna Sharing)
In the same room, on the same WiFi: a Windows 10 machine pulled 50 Mbps while my Fedora laptop was stuck at 2-3 Mbps. Driver, signal, channel, background downloads — all clean. Pinging my own modem showed the problem wasn't out on the internet but between my laptop and the modem; the cause was Bluetooth. I proved it with measurements, and I walk through the two fixes that failed and the mistakes I made building the speed test.
Fixing Fedora Freezing Under Load: zram + Disk Swap + earlyoom
Fedora 44 froze completely under heavy load and only a hard power-off recovered it. Here is how I found the root cause (zram-only, no disk swap) and fixed it for good, step by step. Plus an addendum: how I fixed the SELinux alert my own fix raised two days later.