The sys admin's daily grind: Dnstop

Save the Day

Article from Issue 185/2016
Author(s):

In last month's issue, Charly sent the lean pdnsd DNS cache down the catwalk. To see whether pdnsd really does the work expected of it, he now puts dnstop through infinite rounds in the name of names.

Most distributions include dnstop. If you prefer to build it yourself, you will find the source code online [1], but make sure you download and build the matching Libpcap [2] first. I launched the tool on the computer hosting my DNS cache with the following command:

dnstop -l 3 eth0

The -l 3 parameter tells dnstop to explore name requests up to the third level. For a request like www.linux-magazine.com, com is the first or top-level domain, linux-magazine is thus the second-level domain, and www is the third level.

[...]

Use Express-Checkout link below to read the full article (PDF).

Buy this article as PDF

Express-Checkout as PDF
Price $2.95
(incl. VAT)

Buy Linux Magazine

SINGLE ISSUES
Print Issues
Digital Issues
 
SUBSCRIPTIONS
Print Subs
Digisubs
 
TABLET & SMARTPHONE APPS
Get it on Google Play

US / Canada

Get it on Google Play

UK / Australia

Related content

  • Charly's Column – Pdnsd

    Cache it, if you can! When the latencies of his Internet connection seem to take longer than Napoleon's reign, sys admin Charly comes up with a solution for name resolution.

    more »
  • Top Ten Tops

    The famous Unix admin utility known as Top has many imitators. We take a look at some of the top Top tools.

    more »
  • Charly's Column – Prettyping and Asciiflow

    Columnist Charly is delighted that people still program useful tools for the terminal. Here, he looks at one tool that transforms boring ping data into colorful statistics and another that publishes a construction set for ASCII graphics on the network.

    more »
  • Charly's Column – Searx

    It goes against the economic rationale to assume that commercial search engines have the best interests of users at heart when it comes to data protection and use. Sys admin Charly has found an alternative.

    more »
  • The sys admin's daily grind: Let's Encrypt wildcards

    The pleasure of owning a nice domain like sensorenresidenz.de is clouded by the requirement of an X.509 certificate for every subdomain that the admin wants or has. Columnist Charly can help boost the webmaster's spirits.

    more »
comments powered by Disqus