The entire apartment building appears to have an unusual fiber connection problem. Whenever a device uses a moderate amount of bandwidth—for example, while playing an online game or downloading a file—that device loses internet access completely. Ping tests show 100% packet loss, Windows eventually reports that the connection is disconnected, and it reconnects after roughly 10 seconds before repeating the cycle. The issue affects multiple devices, including phones, and can happen even when the device is close to the router. The Wi-Fi signal itself remains stable, with no obvious interference. The building's ISP-provided router is being used, but a nearby resident using a different router and a different ISP has experienced similar behavior. Ethernet has not been tested yet. What could cause this, and what should we check next?
2 Answers
The key distinction is whether the device loses its local connection or remains connected to Wi-Fi while only internet traffic fails. A stable Wi-Fi signal does not rule out an upstream failure. The fact that PingPlotter shows total packet loss and the device later disconnects suggests the router or an upstream network device may be crashing, rebooting, or dropping its WAN session when traffic increases. Check the router’s event and system logs for reboots, WAN link changes, DHCP errors, or fiber/optical alarms.
First, clarify whether this affects just your unit, the whole building, or possibly the wider complex. Test the same activity over Ethernet as well as Wi-Fi, and compare several devices. Since another resident with different equipment and an entirely different ISP sees the same problem, this sounds less like a faulty home router and more like a shared building network, power, or infrastructure issue. Keep a log of the times, affected devices, and what traffic triggered the failure so the building’s network administrator or ISP can investigate.
It seems to affect the whole building, although I still need to confirm whether nearby buildings have the same issue. It happens on all of my devices, and I’ll test Ethernet next. A resident next door has the same problem despite using different equipment and another ISP.
The device initially still appears connected, but traffic stops completely. After about 10 seconds Windows reports it as disconnected, then it reconnects briefly and the cycle repeats. I’ll check the router logs for resets or WAN errors.