mtr

mtr, short for My Traceroute, is a free, open-source network diagnostic tool that combines the functionality of traceroute and ping. It continuously analyzes the route between the host running mtr and a specified target and presents the results in real time. The name reflects its dual purpose of tracing a path and measuring performance.

Operation and output: mtr sends probes to each hop along the path, collecting latency statistics and detecting packet loss for each hop. The interface shows the hop number and IP address or hostname, along with loss percentage and latency values (last, average, best, worst, and sometimes standard deviation) for the probes. The display updates as new probes are received, enabling quick assessment of where problems occur. It can run in an interactive, curses-based UI, or in non-interactive, report-oriented mode.

Platform and usage: mtr is available on most Unix-like systems (Linux, FreeBSD, macOS) and can be installed via package managers. There are Windows ports and alternatives such as WinMTR. Typical usage is simply “mtr host,” which starts the live analysis. Options include -r for report output and -c to specify the number of probes or cycles, among others, allowing users to tailor duration and detail.

Applications and limitations: It is commonly used to diagnose network latency, packet loss, and routing issues, test reachability to servers, and verify congestion on links. Limitations include reliance on responses from routers; some devices deprioritize or block ICMP or UDP probes, which can skew results or produce incomplete path information. Therefore, mtr is best used alongside other diagnostics rather than as the sole indicator of network health.