mtr
TLDR
Run traceroute to a host
SYNOPSIS
mtr [--report] [--tcp|--udp] [--port num] [--no-dns] [options] hostname
DESCRIPTION
mtr (My TraceRoute) combines the functionality of traceroute and ping into a single network diagnostic tool. It continuously probes each hop along the route to a destination, displaying real-time statistics about packet loss and latency.
The interactive display updates continuously, showing each router hop with loss percentage, sent/received counts, and latency statistics (best, average, worst, standard deviation). This makes it easy to identify where network problems occur.
Report mode (-r) runs a fixed number of cycles and outputs summary statistics, useful for logging and scripting. Output formats include plain text, JSON, XML, and CSV for integration with monitoring systems.
TCP and UDP modes help diagnose issues when ICMP is filtered. Using TCP port 443 or 80 often reaches destinations that block ping. The tool can also detect asymmetric routing and path changes.
MTR is invaluable for diagnosing intermittent network issues - you can watch it over time to catch sporadic packet loss that a single traceroute might miss.
PARAMETERS
-r, --report
Generate report mode output and exit.-c NUM, --report-cycles NUM
Number of pings per hop (default: 10).-s SIZE, --psize SIZE
Packet size in bytes.-T, --tcp
Use TCP SYN packets.-U, --udp
Use UDP datagrams.-P PORT, --port PORT
Target port for TCP/UDP.-n, --no-dns
Do not resolve hostnames.-b, --show-ips
Show both hostname and IP.-w, --report-wide
Wide report format (no truncation).-j, --json
Output in JSON format.-x, --xml
Output in XML format.-C, --csv
Output in CSV format.-i SECONDS, --interval SECONDS
Interval between pings.-m NUM, --max-ttl NUM
Maximum TTL / hops.-f NUM, --first-ttl NUM
Starting TTL.-4
Use IPv4 only.-6
Use IPv6 only.-a ADDRESS, --address ADDRESS
Bind to source address.
CAVEATS
Requires root or capabilities for raw socket access (ICMP/UDP) unless using TCP mode. Some routers don't respond to TTL-exceeded messages, appearing as "???". Rate limiting on routers can cause false packet loss readings. ICMP deprioritization may show higher latency than actual data traffic.
HISTORY
mtr was written by Matt Kimball in 1997 as an improvement over traditional traceroute. The name originally stood for "Matt's TraceRoute." Roger Wolff took over maintenance, adding many features. The tool has become a standard network diagnostic utility, included in most Linux distributions and available for other Unix-like systems and Windows.
SEE ALSO
traceroute(1), ping(1), tracepath(1), nmap(1)
