Hello, Who Are You, Won't You Tell Me Your Name!

Charly's Column – DNSDiag

Article from Issue 220/2019
Author(s):

If some transactions take an inexplicably long time, you don't have to blame yourself for the delayed transmission of user data. Name resolution issues might be to blame. Sys admin Charly has three tools to study the DNS server.

Pure randomness took me by the hand recently and led me to dnsping, dnstraceroute, and dnseval. The tool collection for name resolution is entitled DNSDiag [1]. You need Python 3 and pip3 to install and run the trio and sudo to let it create ICMP sockets.

dnsping lives up to its name, repeatedly querying a DNS server and displaying the response times. The hostname to be resolved is a mandatory parameter. dnsping prompts you for the system's default name server, which can be changed using -s <nameserver>. After typing

sudo dnsping.py -v -s 8.8.8.8 linux-magazine.com

[...]

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 – httpstat

    Httpstat is a special stopwatch you can use to discover how long web servers take to serve up a static or dynamic HTML page. Visible performance lags indicate optimization potential for the server.

    more »
  • Charly's Column

    Using SQL to sift syslog data out of a database is an admittedly universal, but also fairly convoluted approach. phpLogCon, with its web interface, gives admins an easier option.

    more »
  • The sys admin's daily grind: sshuttle

    When he doesn't want to deal with OpenVPN version conflicts or congestion control problems during TCP tunneling, Charly catches a ride on sshuttle.

    more »
  • The sysadmin's daily grind: Pi-hole

    A strange rule seems to dictate that the most useless products and services have the most annoying online advertising. Columnist Charly blocks the garish advertising for all computers on his network centrally with the Pi-hole tool, which is not only for Raspberry Pi devices.

    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 »
comments powered by Disqus