Websites and speed

Find where a connection slows down with traceroute

traceroute shows each router on the path from your Mac to a host, with the time each one takes to answer.

Applies to: All current macOS versions.Checked: 29 October 2026

Symptoms

  • One site or service is slow, but others are fast.
  • You want to know if a delay is in your network or past it.
  • Your provider asks for a trace of the route.

Likely causes

  • Congestion on one part of the route. A delay that starts at one hop and stays to the last hop shows a slow part of the path.
  • Routers that give low priority to probes. One slow hop that recovers at the next hop is usually not a problem.
  • Routers that do not answer. The man page says that an asterisk means no answer before the timeout. Some routers do not send the answers that traceroute needs.

How to check

  1. Open Terminal and trace the route to the host.

    traceroute example.com

    Output One line for each hop, with its address and three response times. An asterisk means that no answer came.

  2. To skip name lookups and get results faster, add -n.

    traceroute -n example.com

  3. If many hops show only asterisks, try ICMP probes with -I.

    traceroute -I example.com

  4. Find the first hop where the times go up and stay up to the end.

  5. Run the trace two or three times. Use the same pattern in all runs, not one result.

How to fix it

  1. If the delay starts at the first hop, examine your Wi-Fi or router. See Slow internet on a Mac: find which part is slow.

  2. If the delay starts in your provider's network, send the trace to your provider.

  3. If the delay starts near the destination, contact the service or wait.

  4. Do not use one slow middle hop as proof. Look at the last hop too.

With Kilobat

  1. Kilobat runs a bounded 12-hop route probe and saves it with the route history.

    kilobat trace example.com

  2. Agents can call the MCP tool trace_route with a host. It returns the same text.

Questions

Why does a hop show * * *?

That router did not answer in time. Many routers do not answer probes. If later hops answer, the path works.

Does traceroute need an administrator password?

No. The default UDP probes and -I work for any user.

Sources

  • traceroute(8), man page installed with macOS 27.2
  • ping(8), man page installed with macOS 27.2

Sources checked on 29 October 2026. Man pages are the ones installed with macOS; open one with man <name> in Terminal.