====== Compare DNS zone on two different DNS servers ======
<code bash> diff <(sort -u <(dig +nottlid +noall +answer @10.0.0.10 example.com TXT -t axfr) ) <(sort -u <(dig +nottlid +noall +answer @10.0.0.11 example.com TXT -t axfr) )</code>
Works in bash

Query txt records with nslookup:
<code bash>set q=txt
c3po._domainkey.altn.com</code>