Network Diagnostic Tools

Network Diagnostic Tools

A full set of browser-based network tools — no install, no account, nothing to configure. Each one runs on its own and answers a specific question, and each has a stable address you can bookmark or paste into a support ticket.

If you are not sure which you need, the short version is below: use the individual tools to answer a factual question about a host, a name or an address, and use the full connection test when you need to know whether your connection will actually carry real-time traffic.

Path and latency

  • Ping — round-trip latency and reachability for any host or IP. Answers "is it up, and how far away?"
  • Traceroute — every router between our servers and a destination, with per-hop latency. Answers "where does the path go, and where does it break?"
  • MTR — traceroute and ping combined and run continuously, so intermittent faults surface that a single trace would miss. This is the one to use for evidence.

DNS

  • DNS lookup — query any record type against the resolver of your choice, which is how you tell a wrong record from a stale cache.
  • DNS trace — follow resolution from the root servers down, to find which delegation step is slow or broken.
  • DNS leak test — see which resolvers actually answered, and whether any belong to your ISP while a VPN is connected.

Address and network identity

  • What is my IP address — your public address, the network that owns it, its ASN, and what geolocation databases claim.
  • AS / ASN lookup — the autonomous system behind any address. The most reliable identity information an IP carries.
  • Reverse DNS — the PTR record published for an address, and the check that matters most for mail delivery.
  • MAC vendor lookup — identify hardware from a MAC address on your local network.

Privacy and interception

  • VPN detection — whether your connection presents as a VPN, proxy or hosting network, and whether the tunnel is genuinely carrying traffic.
  • SSL proxy detection — whether something on your network is intercepting and re-encrypting your HTTPS.

Which tool for which symptom

  • A site will not load — start with DNS lookup. If the record is right, ping the resolved address.
  • Calls or games break up while speed tests look fine — the connection test. Throughput tests hide the loss and jitter that ruin real-time media.
  • Slow only when someone else is downloading — that is queueing under load; see bufferbloat.
  • One destination is bad, everything else is fine — MTR to that destination, then check the return path.
  • You need to prove a fault to your ISP — the guide to doing that explains what evidence gets a ticket escalated rather than closed.

How the tests run

Everything here runs from our servers in San Jose, Ashburn and Hyderabad, or directly from your browser, depending on what is being measured. Nothing needs to be installed and no account is required. Results from the full connection test get a shareable link, which is what makes them useful in a support ticket — the person reading it can open the measurement rather than take your word for it.