Mike’s Traceroute (MTR) – Cisco“Network Transport,” considers TCP.
Ookla’s (and similar) tools test your connection to the Internet, giving you throughput and delay. iPerf tests your network—either locally or to a publicly accessible server—and gives you throughput. Mike’s Traceroute (MTR) shows you the delay and jitter across a network
Note
MTR runs only on Linux-like systems, so if you want to run it on Windows, you must install Windows Subsystem for Linux (WSL), available in the Windows Store.
You can find instructions for installing MTR at https://www.bitwizard.nl/mtr/ or https://github.com/traviscross/mtr. MTR is included in many Linux distributions, so you might not need to install it.
You run MTR using a simple command: mtr x.x.x.x or mtr domain.name. Replace the x.x.x.x with a destination IPv4 address or domain.name with a destination DNS hostname. The host you test connectivity to does not need to run any special software because MTR works like traceroute.
Note
Chapter 15, “Application Transport, ” discusses DNS.
The result of running MTR against a destination will resemble the output in Figure 9-9.
Figure 9-9 MTR Sample Output
Columns of interest in this output are
• Packet Loss: Percentage of packets sent and not answered
• Snt: Packets sent to this destination
• Last: The delay between sending a ping packet to this destination and receiving the response
• Avg: The average delay between sending a ping packet to this destination and receiving the response
• Best: The shortest delay between sending a ping packet to this destination and receiving the response
• Wrst: The longest delay between sending a ping packet to this destination and receiving the response
• StDev: Jitter
MTR uses a traceroute to discover the various routers and hosts along the path and then sends a ping packet to each device. The result is a graph of the average delay and jitter to each device along the path.
Chapter Review
Bandwidth, delay, and jitter are three crucial elements of a network’s performance; each directly impacts applications running over the network. This chapter described the relationship between bandwidth, throughput, and goodput.
While delay is always longer on lower-bandwidth lengths, other factors—specifically queueing—impact delay. Queueing also impacts jitter.
Finally, we described several tools for measuring and understanding throughput, delay, and jitter.
The next chapter turns to network hardware, cabling, and network diagrams—all important topics for network engineers.
One key to doing well on the exams is to perform repetitive-spaced review sessions. Review this chapter’s material using either the tools in the book or interactive tools for the same material found on the book’s companion website. Refer to the online Appendix D, “Study Planner,” element for more details.
Table 9-2 outlines the key review elements and where you can find them. To better track your study progress, record when you completed these activities in the second column.
Table 9-2 Chapter Review Tracking
