I used standalone web server with http-01 challenge mechanism while getting a certificate. Also pointed the domain to the public machine running the LE client. I was able to fetch the certificate.
Later, just to better understand the renewal process, I deleted the DNS A record which pointed the domain to the public machine.
In spite of deleting the A record, I was still able to renew the certificate. Does this mean that during renewal the domain is not resolved by the LE CA? How does LE CA verify domain ownership during certificate renewal? Even during renewal I had to use the standalone plugin which means the LE CA did do the file download, but how did it resolve domain name?
I used following command to renew certificate:
sudo certbot certonly -n --force-renewal --standalone -d ip-172-30-3-207.ssldemo.xyz --standalone-supported-challenges http-01