Network Technologies TCP/IP

Quick Tip: Why Windows traceroute works better than Linux

We noticed when debugging with the always useful tool traceroute (tracert on Windows systems) that we got more responsive results from Windows than from a Linux server on the same or nearby network. Finally I decided to look into it, my Linux pride at stake!

what it is is that Windows tracert utility uses ICMP by default whereas Linux traceroute uses UDP packets. We had been testing on a corporate Intranet where the default firewall policy was to allow ICMP but deny everything else.

The fix
Just add a ‐I switch to your linux traceroute command and the results will be as good as Windows. That switches the packet type to ICMP.

On the Internet where that type of firewall is more uncommon it probably won’t make that much a difference. But on an Intranet it could be just the thing you need.