Let's Encrypt's Imminent Support for IP Address SAN Certificates

Let's Encrypt is nearing the release of certificates supporting IP address Subject Alternative Names (SANs), initially limited to a short-lived (6-day) profile and an allowlist-only approach. The feature is still under development, with no public launch timeline yet. A sample certificate and a website utilizing it are provided, along with discussions about discovered bugs in Firefox and Discourse related to IP address SANs. The post also sparks debate on the validity of using IP addresses as DNS names within SANs and whether the DNS-01 challenge is applicable to IP address certificates.