How to use TRACEROUTE

Updated 6 days ago by Ben Oates

This article is part of our Network troubleshooting series and covers the use of Traceroute.

Traceroute is a tool to help identify the path from one device on the internet to another. It can therefore be useful in identifying at what point on the path between the source and destination an issue is occurring.

Traceroute is available on Windows and Mac computers - and either natively or via an app for other devices.

You can Traceroute an IP address, or a hostname.

General notes

Some hops on a traceroute may show a Request timed out - this is completely normal. Traceroute works by provoking an Internet Control Message Protocol (ICMP) reply from each device along the route, and plenty of routers and firewalls are configured not to send those replies. A hop that does not answer is not necessarily a hop that is broken.

Each hop of the journey is usually a router on the internet passing your traffic along on its way to the destination.

The three numbers shown within each hop are the Round Trip Times (RTT) to that hop.

Sometimes a traceroute will end with several rows of * * * Request timed out. - this doesn't necessarily mean the destination is unreachable - it may be that a firewall, or the device itself is just not responding to ICMP packets.

You may find you can connect to the device with a browser or other application quite successfully.

Windows

1. Open Command Prompt from the Start menu - type cmd and press Enter.
2. The command on windows is tracert
3. The following screenshot shows a traceroute to hera.krystal.co.uk
   tracert hera.krystal.co.uk

   

4. You can view additional options by running the command tracert /?

   

Apple macOS

1. Open Terminal:
   • Go to Applications > Utilities > Terminal or use Spotlight (Cmd + Space) to search for "Terminal."

   

2. Run the Traceroute Command:
   • In the Terminal window, type the following command and hit Enter: traceroute example.com
   • Replace "example.com" with the domain name or IP address you're tracing (e.g., traceroute hera.krystal.co.uk).

   

What can you tell from the Traceroute results

Traceroute can potentially give an indication of where an issue may lie between the source and destination devices.

Sometimes it can be more helpful to have a traceroute in both directions - from source to destination, and destination to source - but this isn't always possible.

If you are reporting a problem to us, trace to your own home server rather than to the example used above - see how to find your home server name. A trace to a different machine tells us nothing about the path to yours. Copy the whole output, including the command line at the top and every hop, and paste it into a ticket from your Client Area; a partial trace usually cannot be interpreted.

It is often worth running PING at the same time - the two together show both whether the destination answers and where the path to it breaks down.

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