3 ms·

Understanding Traceroute [pdf]

73 points by blueatlas 12y ago

handsomeransoms 12y ago
Another (incorrect, but hilariously so) interpretation of the output of traceroute: http://youtu.be/SXmv8quf_xM http://youtu.be/SXmv8quf_xM
- reifnir 12y ago
  Excruciating lol
mct 12y ago
I wrote the original tcptraceroute in 2001. The article mentions many traceroute implementations change the source port to associate queries with responses. Another technique is to use the IP ID field, leaving the source port static. In tcptraceroute, you can choose either method using "--track-id" or "--track-port". By comparing the two, you can sometimes see traffic being load-balanced across multiple links. I just did a quick write up of this at https://gist.github.com/mct/2ae1dbc2d596f59f5aff https://gist.github.com/mct/2ae1dbc2d596f59f5aff (which I should add to the examples.txt file)
jlgaddis 12y ago
From a quick glance, this looks to be a rewrite/reformatting of a presentation at NANOG 47 entitled "Tutorial: How to Accurately Interpret Traceroute Results". From the abstract [0]: > Many people think they understand how to use and understand traceroute, yet the large number of traceroute based tickets at any sizable ISP proves that the vast majority of people do not. Even the ISPs themselves are frequently unable to come up with staff who are qualified to look at a traceroute and interpret it correctly. There's a PDF of the slides [1] as well as a WMV [2] available. As a network engineer at an ISP, I send out these links fairly often. To quote someone else [3]: > This is an incredibly useful presentation. All the little bits and pieces you can't learn from text books. Seriously, watch the video or, at the least, listen to it as you do something else. I'd almost guarantee that you'll learn something. [0]: https://nanog.org/meetings/abstract?id=1442 https://nanog.org/meetings/abstract?id=1442 [1]: https://nanog.org/meetings/nanog47/presentations/Sunday/RAS_Traceroute_N47_Sun.pdf https://nanog.org/meetings/nanog47/presentations/Sunday/RAS_... [2]: https://nanog.org/meetings/nanog47/presentations/breakout%20rooms/TraceRoute_tutorial.wmv https://nanog.org/meetings/nanog47/presentations/breakout%20... [3]: http://lists.usenix.org/pipermail/lisa-members/2009/001426.html http://lists.usenix.org/pipermail/lisa-members/2009/001426.h...

73 points by blueatlas 12y ago

Another (incorrect, but hilariously so) interpretation of the output of traceroute: http://youtu.be/SXmv8quf_xM http://youtu.be/SXmv8quf_xM

reifnir 12y ago
Excruciating lol

mct 12y ago

I wrote the original tcptraceroute in 2001. The article mentions many traceroute implementations change the source port to associate queries with responses. Another technique is to use the IP ID field, leaving the source port static. In tcptraceroute, you can choose either method using "--track-id" or "--track-port". By comparing the two, you can sometimes see traffic being load-balanced across multiple links. I just did a quick write up of this at https://gist.github.com/mct/2ae1dbc2d596f59f5aff https://gist.github.com/mct/2ae1dbc2d596f59f5aff (which I should add to the examples.txt file)

jlgaddis 12y ago

From a quick glance, this looks to be a rewrite/reformatting of a presentation at NANOG 47 entitled "Tutorial: How to Accurately Interpret Traceroute Results". From the abstract [0]: > Many people think they understand how to use and understand traceroute, yet the large number of traceroute based tickets at any sizable ISP proves that the vast majority of people do not. Even the ISPs themselves are frequently unable to come up with staff who are qualified to look at a traceroute and interpret it correctly. There's a PDF of the slides [1] as well as a WMV [2] available. As a network engineer at an ISP, I send out these links fairly often. To quote someone else [3]: > This is an incredibly useful presentation. All the little bits and pieces you can't learn from text books. Seriously, watch the video or, at the least, listen to it as you do something else. I'd almost guarantee that you'll learn something. [0]: https://nanog.org/meetings/abstract?id=1442 https://nanog.org/meetings/abstract?id=1442 [1]: https://nanog.org/meetings/nanog47/presentations/Sunday/RAS_Traceroute_N47_Sun.pdf https://nanog.org/meetings/nanog47/presentations/Sunday/RAS_... [2]: https://nanog.org/meetings/nanog47/presentations/breakout%20rooms/TraceRoute_tutorial.wmv https://nanog.org/meetings/nanog47/presentations/breakout%20... [3]: http://lists.usenix.org/pipermail/lisa-members/2009/001426.html http://lists.usenix.org/pipermail/lisa-members/2009/001426.h...