My 5G home internet dropped up to 97 % of IPv4 packets while IPv6 over the same cell ran clean, and one TCP flow pushed 153 Mbit/s while its neighbors starved. A measurement writeup: what the data shows, what it rules out, the workaround that proves the point, what changed when o2 touched the network on July 16, and what five weeks of continuous monitoring afterwards did and did not settle.

The customer panel hands you a /64 and a gateway, but in the default Virtuozzo container IPv6 is dead on arrival. The fix is a reinstall in KVM mode plus one netplan detail: an on-link default route to a gateway outside your prefix.

Phones kept landing on 192.168.176.x with a gateway that doesn't exist. A tcpdump on the router caught two LSC Smart Connect (Tuya) plugs answering every DHCP discover on the LAN.

Install AusweisApp on CachyOS, then add one UFW broadcast rule so "Smartphone als Kartenleser" pairing actually sees the phone.

Web UI caps the threshold at 70°C. Router idles at 65°C. Here's how to override the fan config over SSH when you suspect heat is causing random restarts.

Adding 7.5 GB of swap via microSD to solve Out of Memory crashes when running AdGuard Home with large blocklists.

Converting an Auerswald COMpact 5020 telephone system from ISDN to VoIP, expanding from 2 to 8 channels.