Error creating new certificate

[schoen]

We have a number of previous threads about not whitelisting validation IP addresses. I guess the most official one is

Failed validation limit, validation IP addresses, and authorization lifetime

H…

@jsha

If you have firewall rules that whitelist specific IP addresses for validation, please be aware that our integration guide warns against that practice, and in the future we will introduce new validation IP addresses more frequently. If you’re unable to open up port 80 or 443 to all IP addresses, you may want to use the DNS challenge instead of the HTTP or TLS-SNI challenges.