Thank you for the answers. More questions: If I run my own DNS cache on 127., 172.16. or 10. then do I have to worry about "cache poisoning"? Do I still need

Thank you for the answers. More questions: If I run my own DNS cache on 127., 172.16. or 10. then do I have to worry about "cache poisoning"? Do I still need to verify authenticity of the answers to my DNS requests? What if I can verify the authenticity of the authoritative DNS servers? If we were somehow able to encrypt the DNS packets between my resolver and authoritative servers on the internet, and I have verified the authenticity of those authoritative servers, should I still have concerns that the answers I get could be forged?