#dns

Windows "The specified domain either does not exist or could not be contacted": it's usually DNS

Fix "The specified domain either does not exist or could not be contacted" when joining a domain: point DNS at a domain controller, test the SRV records, ports and time.

Intermediate · 4 min read

failed to authenticate some domains

Security

Certbot "failed to authenticate some domains": read the Type, then fix DNS, port 80 or the path

Fix Certbot "failed to authenticate some domains": read the error type, then fix DNS records, an IPv6 AAAA record, a closed port 80, the webroot, Cloudflare and CAA.

Intermediate · 5 min read

Temporary failure in name resolution

Networking

"Temporary failure in name resolution": fix DNS on a Linux server

Fix "Temporary failure in name resolution" and "Could not resolve host" on Linux: tell DNS from network problems, check systemd-resolved, and set DNS servers that stick.

Beginner · 4 min read