1. General Results, most used to calculate the result A name "requester.plexseer.net" is subdomain, public suffix is ".net", top-level-domain is ".net", top-level-domain-type is "generic", tld-manager is "VeriSign Global Registry Services", num .net-domains preloaded: 7088 (complete: 175327) A good: All ip addresses are public addresses Warning: Only one ip address found: requester.plexseer.net has only one ip address. Warning: No ipv6 address found. Ipv6 is the future with a lot of new features. So every domain name should have an ipv6 address. See https://en.wikipedia.org/wiki/IPv6: requester.plexseer.net has no ipv6 address. A good: No asked Authoritative Name Server had a timeout A DNS: "Name Error" means: No www-dns-entry defined. This isn't a problem A good - only one version with Http-Status 200 HSTS-Preload-Status: unknown. Domain never included in the Preload-list. Check https://hstspreload.org/ to learn some basics about the Google-Preload-List. A Good: Some urls with http status 200/404 have a complete Content-Type header (MediaType / MediaSubType + correct charset):1 complete Content-Type - header (2 urls) http://requester.plexseer.net/.well-known/acme-challenge/check-your-website-dot-server-daten-dot-de 23.84.119.53 Url with incomplete Content-Type - header - missing charset http://requester.plexseer.net/Main unraid_d3b9faf1dcc42a5130841edd56cb978c=076d29ceff4c15e2f8f21861ddffafcf; path=/; HttpOnly; SameSite=Lax Fatal: Cookie sent via http. Never send Cookies / Session-Cookies via http. If a user uses an insecure WLan and if the same cookie is used to managed the authenticated session, it's possible to hack that user. Same with HttpOnly - without https that's only decorative. D http://requester.plexseer.net/ 23.84.119.53 http://requester.plexseer.net/Main Wrong redirect one domain http to other domain http. First redirect to https without changing the domain, so no new dns query is required. So the server can send the HSTS header. That's fundamental using HSTS (Http Strict Transport Security). First step: Add correct redirects http ⇒ https. Perhaps in your port 80 vHost something like "RewriteEngine on" + "RewriteRule ^ https://%{SERVER_NAME}%{REQUEST_URI} [END,QSA,R=permanent]" (two rows, without the "). Don't add this in your port 443 vHost, that would create a loop. Then recheck your domain, should be Grade C. There is the rule to select one https version as preferred version. H fatal error: No https - result with http-status 200, no encryption H Fatal error: http result with http-status 200, no encryption. Add a redirect http ⇒ https, so every connection is secure. Perhaps in your port 80 vHost something like "RewriteEngine on" + "RewriteRule ^ https://%{SERVER_NAME}%{REQUEST_URI} [END,QSA,R=permanent]" (two rows, without the "). Don't add this in your port 443 vHost, that would create a loop. V https://requester.plexseer.net/ 23.84.119.53 connect failure - perhaps firewall V https://23.84.119.53/ 23.84.119.53 connect failure - perhaps firewall X Fatal error: Nameserver doesn't support TCP connection: ns1.duckdns.org / 99.79.143.35: Timeout X Fatal error: Nameserver doesn't support TCP connection: ns2.duckdns.org / 35.182.183.211: Timeout X Fatal error: Nameserver doesn't support TCP connection: ns3.duckdns.org / 35.183.157.249: Timeout X Fatal error: Nameserver doesn't support TCP connection: ns4.duckdns.org / 3.97.51.116: Timeout X Fatal error: Nameserver doesn't support TCP connection: ns5.duckdns.org / 99.79.16.64: Timeout X Fatal error: Nameserver doesn't support TCP connection: ns6.duckdns.org / 3.97.58.28: Timeout Info: Checking the ip addresses of that domain name not exact one certificate found. So it's impossible to check if that domain requires Server Name Indication (SNI).: Domain requester.plexseer.net, 1 ip addresses. 2. DNS- and NameServer - Checks A Info:: 13 Root-climbing DNS Queries required to find all IPv4- and IPv6-Addresses of 4 Name Servers. A Info:: 13 Queries complete, 13 with IPv6, 0 with IPv4. A Good: All DNS Queries done via IPv6. Ok (4 - 8):: An average of 3.3 queries per domain name server required to find all ip addresses of all name servers. A Info:: 4 different Name Servers found: ns-cloud-e1.googledomains.com, ns-cloud-e2.googledomains.com, ns-cloud-e3.googledomains.com, ns-cloud-e4.googledomains.com, 4 Name Servers included in Delegation: ns-cloud-e1.googledomains.com, ns-cloud-e2.googledomains.com, ns-cloud-e3.googledomains.com, ns-cloud-e4.googledomains.com, 4 Name Servers included in 1 Zone definitions: ns-cloud-e1.googledomains.com, ns-cloud-e2.googledomains.com, ns-cloud-e3.googledomains.com, ns-cloud-e4.googledomains.com, 1 Name Servers listed in SOA.Primary: ns-cloud-e1.googledomains.com. A Good: Only one SOA.Primary Name Server found.: ns-cloud-e1.googledomains.com. A Good: SOA.Primary Name Server included in the delegation set.: ns-cloud-e1.googledomains.com. A Good: All Name Server Domain Names have a Public Suffix. A Good: All Name Server Domain Names ending with a Public Suffix have minimal one IPv4- or IPv6 address. A Good: All Name Server ip addresses are public. A A Info: IPv6-Subnet-list: 4 Name Servers with IPv6, 1 different subnets (first block): 2001:, 1 different subnets (first two blocks): 2001:4860:, 1 different subnets (first three blocks): 2001:4860:4802:, 4 different subnets (first four blocks): 2001:4860:4802:0032:, 2001:4860:4802:0034:, 2001:4860:4802:0036:, 2001:4860:4802:0038: A Good: Name Server IPv6 addresses from different subnets found. A Good: Nameserver supports TCP connections: 4 good Nameserver A Good: Nameserver supports Echo Capitalization: 4 good Nameserver A Good: Nameserver supports EDNS with max. 512 Byte Udp payload, message is smaller: 4 good Nameserver A Good: Nameserver has passed 10 EDNS-Checks (OP100, FLAGS, V1, V1OP100, V1FLAGS, DNSSEC, V1DNSSEC, NSID, COOKIE, CLIENTSUBNET): 4 good Nameserver Nameserver doesn't pass all EDNS-Checks: ns1.duckdns.org / 99.79.143.35: OP100: ok. FLAGS: ok. V1: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found. V1OP100: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found, no OPT100 expected, no OPT100 found. V1FLAGS: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found. DNSSEC: ok. V1DNSSEC: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found. NSID: ok. COOKIE: ok. CLIENTSUBNET: ok. Nameserver doesn't pass all EDNS-Checks: ns1.duckdns.org / 99.79.143.35: OP100: ok. FLAGS: ok. V1: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found. V1OP100: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found, no OPT100 expected, no OPT100 found. V1FLAGS: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found. DNSSEC: ok. V1DNSSEC: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found. NSID: ok. COOKIE: ok. CLIENTSUBNET: ok. Nameserver doesn't pass all EDNS-Checks: ns2.duckdns.org / 35.182.183.211: OP100: ok. FLAGS: ok. V1: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found. V1OP100: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found, no OPT100 expected, no OPT100 found. V1FLAGS: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found. DNSSEC: ok. V1DNSSEC: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found. NSID: ok. COOKIE: ok. CLIENTSUBNET: ok. Nameserver doesn't pass all EDNS-Checks: ns2.duckdns.org / 35.182.183.211: OP100: ok. FLAGS: ok. V1: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found. V1OP100: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found, no OPT100 expected, no OPT100 found. V1FLAGS: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found. DNSSEC: ok. V1DNSSEC: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found. NSID: ok. COOKIE: ok. CLIENTSUBNET: ok. Nameserver doesn't pass all EDNS-Checks: ns3.duckdns.org / 35.183.157.249: OP100: ok. FLAGS: ok. V1: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found. V1OP100: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found, no OPT100 expected, no OPT100 found. V1FLAGS: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found. DNSSEC: ok. V1DNSSEC: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found. NSID: ok. COOKIE: ok. CLIENTSUBNET: ok. Nameserver doesn't pass all EDNS-Checks: ns3.duckdns.org / 35.183.157.249: OP100: ok. FLAGS: ok. V1: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found. V1OP100: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found, no OPT100 expected, no OPT100 found. V1FLAGS: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found. DNSSEC: ok. V1DNSSEC: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found. NSID: ok. COOKIE: ok. CLIENTSUBNET: ok. Nameserver doesn't pass all EDNS-Checks: ns4.duckdns.org / 3.97.51.116: OP100: ok. FLAGS: ok. V1: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found. V1OP100: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found, no OPT100 expected, no OPT100 found. V1FLAGS: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found. DNSSEC: ok. V1DNSSEC: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found. NSID: ok. COOKIE: ok. CLIENTSUBNET: ok. Nameserver doesn't pass all EDNS-Checks: ns4.duckdns.org / 3.97.51.116: OP100: ok. FLAGS: ok. V1: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found. V1OP100: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found, no OPT100 expected, no OPT100 found. V1FLAGS: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found. DNSSEC: ok. V1DNSSEC: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found. NSID: ok. COOKIE: ok. CLIENTSUBNET: ok. Nameserver doesn't pass all EDNS-Checks: ns5.duckdns.org / 99.79.16.64: OP100: ok. FLAGS: ok. V1: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found. V1OP100: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found, no OPT100 expected, no OPT100 found. V1FLAGS: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found. DNSSEC: ok. V1DNSSEC: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found. NSID: ok. COOKIE: ok. CLIENTSUBNET: ok. Nameserver doesn't pass all EDNS-Checks: ns5.duckdns.org / 99.79.16.64: OP100: ok. FLAGS: ok. V1: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found. V1OP100: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found, no OPT100 expected, no OPT100 found. V1FLAGS: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found. DNSSEC: ok. V1DNSSEC: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found. NSID: ok. COOKIE: ok. CLIENTSUBNET: ok. Nameserver doesn't pass all EDNS-Checks: ns6.duckdns.org / 3.97.58.28: OP100: ok. FLAGS: ok. V1: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found. V1OP100: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found, no OPT100 expected, no OPT100 found. V1FLAGS: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found. DNSSEC: ok. V1DNSSEC: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found. NSID: ok. COOKIE: ok. CLIENTSUBNET: ok. Nameserver doesn't pass all EDNS-Checks: ns6.duckdns.org / 3.97.58.28: OP100: ok. FLAGS: ok. V1: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found. V1OP100: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found, no OPT100 expected, no OPT100 found. V1FLAGS: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found. DNSSEC: ok. V1DNSSEC: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found. NSID: ok. COOKIE: ok. CLIENTSUBNET: ok. Nameserver doesn't pass all EDNS-Checks: ns-cloud-e1.googledomains.com: OP100: no result. FLAGS: no result. V1: no result. V1OP100: no result. V1FLAGS: no result. DNSSEC: no result. V1DNSSEC: no result. NSID: no result. COOKIE: no result. CLIENTSUBNET: no result. A Good: All SOA have the same Serial Number Warning: No CAA entry with issue/issuewild found, every CAA can create a certificate. Read https://en.wikipedia.org/wiki/DNS_Certification_Authority_Authorization to learn some basics about the idea of CAA. Your name server must support such an entry. Not all dns providers support CAA entries. 3. Content- and Performance-critical Checks A Good: All checks /.well-known/acme-challenge/random-filename without redirects answer with the expected http status 404 - Not Found. Creating a Letsencrypt certificate via http-01 challenge should work. If it doesn't work: Check your vHost configuration (apachectl -S, httpd -S, nginx -T). Every combination of port and ServerName / ServerAlias (Apache) or Server (Nginx) must be unique. Merge duplicated entries in one vHost. If you use an IIS, extensionless files must be allowed in the /.well-known/acme-challenge subdirectory. Create a web.config in that directory. Content: <configuration><system.webServer><staticContent><mimeMap fileExtension="." mimeType="text/plain" /></staticContent></system.webServer></configuration>. If you have a redirect http ⇒ https, that's ok, Letsencrypt follows such redirects to port 80 / 443 (same or other server). There must be a certificate. But the certificate may be expired, self signed or with a not matching domain name. Checking the validation file Letsencrypt ignores such certificate errors. Trouble creating a certificate? Use https://community.letsencrypt.org/ to ask. A Info: No img element found, no alt attribute checked A Good: Domainname is not on the "Specially Designated Nationals And Blocked Persons List" (SDN). That's an US-list of individuals and companies owned or controlled by, or acting for or on behalf of, targeted countries. It also lists individuals, groups, and entities, such as terrorists and narcotics traffickers designated under programs that are not country-specific. Collectively, such individuals and companies are called "Specially Designated Nationals" or "SDNs." Their assets are blocked and U.S. persons are generally prohibited from dealing with them. So if a domain name is on that list, it's impossible to create a Letsencrypt certificate with that domain name. Check the list manual - https://www.treasury.gov/resource-center/sanctions/sdn-list/pages/default.aspx A Duration: 871926 milliseconds, 871.926 seconds