What is an MTR?

Network administration and troubleshooting go hand in hand! If you are a network administrator, you would probably be aware of the two most popular troubleshooting tools, Ping and Traceroute. The latest in the series is My Traceroute (MTR) originally Matt’s traceroute. It has evolved to become one of the most popular online Tracerouting tools. Along with all the features of Ping and Traceroute bundled together, it also comes with added features while being lightweight to use.

Overview

The MTR network monitor is a computer application that combines the availability measurement feature of Ping with Traceroute’s hop-to-hop analysis. MTR makes use of the Internet Control Message Protocol (ICMP) to measure the device availability and hop to hop jump time. The distinguishing feature of MTR is that it can track packet loss and jitter well. Thus, MTR can measure the quality of connection, and transfer time and loss of packets in the route.

Using the performance monitor, you can generate and view performance data reports. The report is generated from the network and fed back to an infographic table of packet loss and latency.

How is MTR Useful?

MTR is a useful tool for a number of reasons. First, it combines Ping and Traceroute together to be able to measure the availability of devices on the network as well as monitoring the route. However, it also has a significant advantage over Traceroute because the output is updated continuously. With Traceroute, you have to update scans manually to measure how a network’s performance changes over time.

In contrast, you can run MTR and your information will be connected until you say stop. Being able to monitor the change in network performance over time helps when it comes to troubleshooting.

You can install MTR for your operating system from here.

How To Use MTR

To view your traffic data, you first need to generate a MTR report using its network scanner. MTR reports are bi-directional, thus generating reports to and from both ends. When using the MTR network scanner, you need to generate an MTR report in order to view your traffic data.

Generating Reports

Windows (with WinMTR)

Firstly, go to the ‘host’ field and enter your domain. Next, click on Start. Once done, packets shall be transmitted and continue until manually terminated. The packets data is displayed on the dashboard, showing details of packets uploaded and downloaded along with the packet loss percentage.

Linux

Using the Command Lind Interface (CLI) of MTR on Linux, you can generate an MTR report by typing mtr followed by the url to be analyzed.

For example:

• mtr facebook.com

Reading MTR reports

After generating the MTR report, the next important task is to read and analyze the results of the report. In the report generated, it specifies where the packets are being sent on the network (in our case, on facebook.com ). The info results can be analyzed as follows:

• Hops: The index lines on the left side of the screen.
• Host names: The names right of the index numbers.
• Loss%: The Loss % column displays the packets loss as percentage.
• Snt: The Snt column displays the number of packets sent.
• Latency details: Last, Avg, Best, and Worst are metrics to measure the latency in ms. Here, Last measures the latency of the last packet sent, Avg measures the average latency of the packets sent, and Best and Worst packets measure the lowest and highest round-trip time for transmitted packets.

How to Measure Packet loss with MTR

On the MTR network monitor, the numerical values under the Loss% column best depict the loss of packets in transmission. However while using the MTR, remember to watch out for the limiting. Limiting comes when the network service providers put a cap on the amount of ITo measure packet loss on the MTR network monitor.

ICMP rate limiting is set by the network service providers to prioritize one network traffic over the other. This limit affects the MTR reports, which in turn, shows packet loss which actually isn’t because of wrong configuration but because of the service provider imposing caps on ICMP traffic.

How to be sure the packets loss is due to cap set by the service provider

The best way is to compare the packets lost between the hops. If one hop has a high packet loss but the other neighbouring hops show packet loss straight down to 0%, then most certainly the case is the limit on the MTR. As a standard rule, it is advised to trust the hops method if you find variable rates of packet loss.

If you have been troubleshooting for a particular issue on the network and want to be sure of the packets being lost in both the directions to and fro, you would be better able to detect problems on the return or outside route than the send route.

Measuring Latency with MTR

The latency is one of the most important and precise metrics to interpret from the MTR reports. But finding the latency is dependent on manual measurement of a number of other factors.

• Firstly, when reading a report, pay close attention to numbers such as hops, last, best, worst, and average latency in each stage and look out for any anomalies. For example, if you observe a latency jump up drastically between two different hops, this error is probably due to one part of the network. However, another possibility is the latency being caused due to the return route packets.
• The return route reports are not displayed in the MTR report. Instead, you would have to look out for differences between the final hop and the one just before and look for any problems. You would have to run the troubleshooting again to diagnose the particular problem.

Measuring jitters on MTR

MTR can also be used to measure network jitters. It is not directly available on the main report page but to view it, you would have to enter another option command:

• or -order

This command helps determine what fields are to be displayed and in what order. The list of fields available are:

• L – Loss ratio
• D – Dropped packets
• R – Received packets
• S – Sent packets
• N – Newest RTT (ms)
• B – Min/Best RTT (ms)
• A – Average RTT (ms)
• W – Max/Worst RTT (ms)
• V – Standard Deviation
• G – Geometric Mean
• J – Current Jitter
• M – Jitter Mean/Avg.
• X – Worst Jitter
• I -Interarrival Jitter

With that, we have discussed and analyzed the MTR tool, used as a network troubleshooting tool that combines features of Ping and Traceroute with an added topping of its custom features. Happy troubleshooting!