Home·Terminal commands

mtr

Networking

Usage

mtr -rwc <count> <host>

Merges traceroute and ping into one continuously updated table, the right tool for intermittent packet loss; loss shown at a middle hop is usually just that router rate-limiting its replies, and only loss that continues to the final hop is real.

Common flags

FlagMeaning
-rReport mode: run, print a table and exit. Made for pasting into a ticket.
-c 100How many cycles to run before reporting.
-wWide report so long host names are not cut off.
-nNo reverse DNS.
-T -P 443Probe with TCP to a real port instead of ICMP.
-bShow both the host name and the address.

Examples

mtr -rwc 100 8.8.8.8

A hundred cycles summarised, the report to attach to a complaint.

sudo mtr -T -P 443 example.com

Trace with TCP when ICMP is filtered.

When a connection fails, these narrow down how far it got — name not resolving, no route, or a blocked port.

How to read this

  • Square brackets [ ] mark a part you may leave out.
  • An ellipsis … means you can list more than one.
  • Flags are case-sensitive — in some commands -r and -R do different things.

Questions

Q. What does mtr do?

Merges traceroute and ping into one continuously updated table, the right tool for intermittent packet loss; loss shown at a middle hop is usually just that router rate-limiting its replies, and only loss that continues to the final hop is real.

Q. How do I type it?

mtr -rwc <count> <host> — square brackets mark the parts you can leave out.

Q. How many flags are worth knowing?

6 are listed here; the full set is in man mtr. This command sits under Networking.

Related commands

man page: man mtr