I'm having the following issue:

Running tracert from Windows 7 returns all the hops to a given server. Running traceroute from Fedora 30, using the same connection and the same destination, beyond the gateway IP it returns only * * *.

Could you please explain me why from Windows it is working, but from Fedora is not? What is the difference?

Also, can you advise me how can I make traceroute return hops when being ran from Fedora?

  • maybe there something like iptables or any other firewall enabled on your Linux client. check your firewall and make sure no rules are defined. – Zareh Kasparian Oct 19 at 9:10

Windows' tracert is using ICMP while incrementing TTL to do probes:

How to Use the TRACERT Utility

The TRACERT diagnostic utility determines the route to a destination by sending Internet Control Message Protocol (ICMP) echo packets to the destination.

Fedora's traceroute, by default, sends UDP probes, as have been previous Unix traceroute implementations doing. The hint UDP is default (beside having double-checked by doing a capture before writing this answer) is from man which talks first about UDP:

We don't want the destination host to process the UDP probe packets, so the destination port is set to an unlikely value (you can change it with the -p flag). There is no such a problem for ICMP or TCP tracerouting (for TCP we use half-open technique, which prevents our probes to be seen by applications on the destination host).

Both tools expect to receive ICMP TIME EXCEEDED as response to build the route.

Along this path, various routers may choose to answer differently (ie: not at all) depending on the probe method used.

If you know that ICMP probes work better for your test, you can do the same on Fedora with:

traceroute --icmp destination

As ICMP, contrary to UDP, usually requires crafting special packets, the command might require root privileges to run with this option.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.