My internet connection starts out normally, but after a short time it slows to a crawl. Restarting both my Windows 11 laptop and router temporarily fixes it, although the slowdown quickly returns.
I checked Windows Update and confirmed that nothing is currently downloading. I also looked for other background software using the connection. The issue happens in both Firefox with extensions disabled and Chrome without extensions, so it does not appear to be browser-specific.
During the slowdown, pinging 8.8.8.8 produced no packet loss, but latency ranged from 624 to 1419 ms, averaging 1052 ms. Traceroute showed the delay beginning at the first provider hop after my router, with later hops also affected. My router itself responds in about 2–3 ms.
I have also installed Wireshark and TCPView, but I am not sure how to use them to identify the cause. My ISP appears to be Orange, and I am currently using Cloudflare DNS at 1.1.1.1. What should I test next, and does this point to a problem with my computer, router, Wi-Fi connection, or ISP?
3 Answers
Changing DNS probably will not fix this. DNS only affects name lookups, while you are pinging the numeric address 8.8.8.8 directly. The very high response times indicate a latency problem rather than a DNS problem. Try the same tests against your router, then your ISP gateway if you know its address, and another public IP. Also repeat them on a wired Ethernet connection if possible; if Ethernet is normal while Wi-Fi is slow, investigate wireless interference or the Wi-Fi adapter.
The traceroute strongly suggests the problem begins beyond your own router, at or near the ISP network. Your router replies in just a few milliseconds, while the next hop is already hundreds or thousands of milliseconds away. Since the high latency continues through the rest of the route, this looks more like congestion or a fault in the ISP access network than a browser or Windows issue. Contact Orange and provide the ping and traceroute results. Ask them to check the line, router connection, and local network congestion.
The missing response at one traceroute hop is not automatically a problem because routers often deprioritize or block traceroute replies. The important detail is that the latency is already very high at the first hop outside your home and remains high afterward. Before calling the ISP, disconnect other devices, temporarily stop cloud-sync or game-launcher software, and check whether the router reports a weak signal or a large number of connected clients. If the issue occurs on multiple devices, that further supports an ISP or router-line problem rather than a Windows application.
That makes sense. I wanted to rule out a local configuration problem first, but the delay does seem to start immediately after the router.