![]() ![]() A large loss will indicate a problem with the particular router. 0.0% 21.9 23.7 19.2 29.9 3.6īoth packet loss and latency tell you a lot about the quality of your connections. You can ask for a report using syntax like this: mtr -report ī Snt: 10 Loss% Last Avg Best Wrst StDev Instead, it runs through 10 iterations (or whatever you tell it using the -c (count) or -report-cycles option and shows you the result at the end. This gives you a static report (rather than updating every second). 0.0% 23.3 22.2 21.1 23.3 1.5Īnother often used mtr command is to use the -r or -report command. ![]() Keys: Help Display mode Restart statistics Order of fields quitģ. Last, Avg, Best, and Wrst are all provided in milliseconds My traceroute Loss%-percentage of packets lost at each hop (can change with -report-cycles=# where # is replaced by the number of packets you want to send.The columns in the output (see example below) represent: The mtr command also shows you a number of statistics for each leg in the route. It also shows you the packet loss, like ping. You can slow this down by giving the command a -i or -interval argument and specify the seconds you want to pass between each update. First, like top, it provides a table of values that refreshes itself every second or so, allowing you to see how the values are updated over time. The mtr command differs from traceroute in several ways. Here is some sample traceroute output: $ traceroute The latency (round trip) measurement is the timestamp when ICMP reply is received minus the timestamp when the probe was launched.īy default, traceroute issues three probes aper hop, thus you will see three numbers for each hop in the traceroute output. Instead, an “ICMP TTL exceeded” event occurs just it has once at each of the other devices, measurements for the last device are sent back to the source and the report is done. At the final device, it becomes 0 and the tracing goes no further. ![]() At each connection, the router decrements the TTL by one (this is what routers always do). When it sets the TTL to 2, for example, it gets the timing information for the second leg. Each time, it collects the round trip time for the next leg of the trip to the remote system. It does this by setting the TTL to 1, then 2, then 3 and so on. Like traceroute, mtr uses TTLs (time to live values) so that it can report on each leg of a route individually. Ubuntu or Debian systems: apt-get install mtr.If you do, here are some commands for doing so: While traceroute is likely to be installed on every Unix system you use, you may have to separately install mtr. Like ping and traceroute, mtr uses icmp packets to test connections. The mtr tool-“my traceroute”, originally “Matt’s traceroute” for the guy that first developed it (Matt Kimball in 1997)-is in some ways like a combination of traceroute and ping and it provides a lot more data than the two of these commands combined. ![]()
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