For a project I need a certificate for usage within a local network. I am using a .LAN domain name and it seems not to be possible to use this top level domain. At this moment, all PC’s in the local network receive a warning about an insecure website. What would you advise in this situation?
Let’s Encrypt is only able to issue certificates for true top level domains registered with IANA. In this case,.lan is not an IANA registered top level domain and so you won’t be able to get a certificate from Let’s Encrypt for this domain.