A common symptom misdiagnosed as "slow internet" is actually DNS resolution latency. When a user navigates to a website, the browser must resolve the domain to an IP address. If the ISP's default DNS servers are under heavy load or geographically distant, this lookup can add 100ms+ to every single web request. The Diagnostic Process To determine if DNS is the bottleneck, bypass the domain layer entirely. If navigating directly to an IP address (e.g., https://1.1.1.1) is instantaneous, but navigating to https://google.com hangs on "Resolving host", the local DNS cache or upstream forwarder is failing. Bypassing ISP DNS Hooks Many consumer routers strictly intercept port 53 traffic, forcing all LAN devices to use the ISP's sluggish resolvers. As part of the network infrastructure upgrades I run for local businesses in Sunningdale, I configure the primary DHCP scope to hand out high-performance, privacy-respecting public resolvers: Cloudflare: 1.1.1.1 and 1.0.0.1 (See Cloudflare DNS Docs) Quad9: 9.9.9.9 (Built-in threat blocking) Validating the Resolution Path You can validate which server is answering queries using nslookup: nslookup google.com If the Server response is your local router gateway (e.g., 192.168.1.1), your router is proxying the requests. Proper configuration requires the router to pass the upstream DNS addresses directly to the client devices via DHCP. For more information on establishing stable baseline metrics for troubleshooting, see my guide on FTTP Latency Baselines.