Windows
nslookup
Built in. Use -type= for record types and -vc for TCP.
Find out who is interfering with your DNS
Queries sent to @dnsp.co come back with debugging information instead of real addresses. These results let you find out if your answers are being rewritten, which machines are really asking on your behalf, and what your DNS resolver discloses about you.
Nothing to install. You query our nameserver from a terminal.
FIG. 01: The basic test
run these
$ dig @dnsp.co www.example.org +short
123.45.67.89
$ dig @dnsp.co www.example.org AAAA +short
1111:2222:3333:4444:5555:6666:7777:8888
Those two answers are fixed, for every name, forever. Pick any domain you are suspicious about and substitute it.
FIG. 02: Reading the result
123.45.67.89
Clean
Your query reached us and the answer came back unmodified.
93.184.216.34
Redirected
A real-looking address means your query never arrived here. Something answered on our behalf.
;; no servers could be reached
Blocked
Outbound DNS to anything but the local resolver is being dropped. Try UDP/10053.
FIG. 03: Your tool
macOS
dig / host
Both ship with the system. dig gives the fullest output.
Linux
dig / host
From bind-utils or dnsutils, depending on distribution.
Syntax differs between these tools. If you need help, use the query builder to generate the correct syntax for your system.
Not sure which test you need?
Pick the symptom, get the exact command for your shell, and read what the answer means.