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

Charly's Column – DNSDiag

Article from Issue 220/2019

Author(s): Charly Kühnast

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

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