Query Wikipedia by issuing a DNS query for a TXT record. The TXT record will also include a short URL to the complete corresponding Wikipedia entry.You can also write a little shell script like: $ cat wikisole.sh #!/bin/sh dig +short txt ${1}.wp.dg.cx and run it like ./wikisole.sh unix were your first option ($1) will be used as search term. Show Sample Output

Instead of opening your browser, googling "whatismyip"... Also useful for scripts. dig can be found in the dnsutils package.

It's somewhat common ISPs to intercept DNS queries at port 53 and resolve them at their own. To check if your ISP is intercepting your DNS queries just type this command in the terminal. "#.abc" it's an OK answer. But if you get something like "I am not an OpenDNS resolver.", yep, you are beign cheated by your ISP.

Shorter version, works with multiple words. Show Sample Output

The +short option should make dig less chatty.

Will edit *.db files in the same directory with todays date. Useful for doing a mass update to domains on a nameserver, adding spf records, etc. Looks for a string starting with 200 or 201 followed by 7 numbers, and replaces with todays date. This won't overwrite Ip's but i would still do some double checking after running this. Make sure your server's date is correct, otherwise insert your own serial number. rndc reload should usually follow this command.

Since systemd-resolved was implemented, add a DNS server have become weirder and harder than before. With this command, you can add a DNS server on-the-fly tied to an specific interface

This command uses nmap to perform reverse DNS lookups on a subnet. It produces a list of IP addresses with the corresponding PTR record for a given subnet. You can enter the subnet in CDIR notation (i.e. /24 for a Class C)). You could add "--dns-servers x.x.x.x" after the "-sL" if you need the lookups to be performed on a specific DNS server. On some installations nmap needs sudo I believe. Also I hope awk is standard on most distros. Show Sample Output

Show Sample Output

Simple command to trace a DNS query from the root all the way to the authoritative servers.

google has added 2 more netblocks... Show Sample Output

I'm just a simple programmer. I find dig too verbose. host tells me alias(es) and IP address in a quick to grok format with nothing special to remember for input parameters. With thanks to http://www.cyberciti.biz/faq/how-to-test-or-check-reverse-dns/ Show Sample Output

Change the $domain variable to whichever domain you wish to query. Works with the majority of whois info; for some that won't, you may have to compromise: domain=google.com; for a in $(whois $domain | grep "Domain servers in listed order:" --after 3 | grep -v "Domain servers in listed order:"); do echo ">>> Nameservers for $domain from $a Note that this doesn't work as well as the first one; if they have more than 3 nameservers, it won't hit them all. As the summary states, this can be useful for making sure the whois nameservers for a domain match the nameserver records (NS records) from the nameservers themselves. Show Sample Output

Occasionally, to force zone updating, cache flush is necessary. The use of this command is better than restart the Bind9 process.

Occasionally, to force zone updating, cache flush is necessary. This command is better than restart the mydns daemon.