1. General Results, most used to calculate the result A name "cs2-guide.com" is domain, public suffix is ".com", top-level-domain is ".com", top-level-domain-type is "generic", tld-manager is "VeriSign Global Registry Services", num .com-domains preloaded: 86299 (complete: 221801) A Good: All ip addresses are public addresses A Good: Minimal 2 ip addresses per domain name found: cs2-guide.com has 2 different ip addresses (authoritative). A Good: Minimal 2 ip addresses per domain name found: www.cs2-guide.com has 2 different ip addresses (authoritative). A Good: Ipv4 and Ipv6 addresses per domain name found: cs2-guide.com has 1 ipv4, 1 ipv6 addresses A Good: Ipv4 and Ipv6 addresses per domain name found: www.cs2-guide.com has 1 ipv4, 1 ipv6 addresses A Good: No asked Authoritative Name Server had a timeout A Good: No cookie sent via http. 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: All urls with http status 200/404 have a complete Content-Type header (MediaType / MediaSubType + correct charset) 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. A Good: More then one ip address per domain name found, checking all ip addresses the same http status and the same certificate found: Domain cs2-guide.com, 2 ip addresses. A Good: More then one ip address per domain name found, checking all ip addresses the same http status and the same certificate found: Domain www.cs2-guide.com, 2 ip addresses. 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 cs2-guide.com, 2 ip addresses. 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 www.cs2-guide.com, 2 ip addresses. B No _mta-sts TXT record found (mta-sts: Mail Transfer Agent Strict Transport Security - see RFC 8461). Read the result of server-daten.de (Url-Checks, Comments, Connections and DomainServiceRecords) to see a complete definition. Domainname: _mta-sts.cs2-guide.com 2. Header-Checks (alpha, started 2022-10-23, may be buggy / incomplete) U No https result with http status 2** or 4** (standard-check) found, no header checked. 3. DNS- and NameServer - Checks A Info:: 12 Root-climbing DNS Queries required to find all IPv4- and IPv6-Addresses of 2 Name Servers. A Info:: 12 Queries complete, 8 with IPv6, 4 with IPv4. Warning: Only some DNS Queries done via ipv6. IPv6 is the future, so the name servers of your name servers should have ipv6 addresses. Ok (4 - 8):: An average of 6.0 queries per domain name server required to find all ip addresses of all name servers. A Info:: 2 different Name Servers found: ns3.stratoserver.net, ns4.stratoserver.net, 2 Name Servers included in Delegation: ns3.stratoserver.net, ns4.stratoserver.net, 2 Name Servers included in 1 Zone definitions: ns3.stratoserver.net, ns4.stratoserver.net, 1 Name Servers listed in SOA.Primary: ns3.stratoserver.net. A Good: Only one SOA.Primary Name Server found.: ns3.stratoserver.net. A Good: SOA.Primary Name Server included in the delegation set.: ns3.stratoserver.net. A Good: Consistency between delegation and zone. The set of NS records served by the authoritative name servers must match those proposed for the delegation in the parent zone. Ordered list of name servers: ns3.stratoserver.net, ns4.stratoserver.net 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 Good: Minimal 2 different name servers (public suffix and public ip address) found: 2 different Name Servers found A Good: All name servers have ipv4- and ipv6-addresses.: 2 different Name Servers found Warning: All Name Servers have the same Top Level Domain / Public Suffix. If there is a problem with that Top Level Domain, your domain may be affected. Better: Use Name Servers with different top level domains.: 2 Name Servers, 1 Top Level Domain: net Warning: All Name Servers have the same domain name. If there is a problem with that domain name (or with the name servers of that domain name), your domain may be affected. Better: Use Name Servers with different domain names / different top level domains.: Only one domain name used: stratoserver.net A Good: Name servers with different Country locations found: 2 Name Servers, 2 Countries: DE, ES A Info: Ipv4-Subnet-list: 2 Name Servers, 2 different subnets (first Byte): 185., 217., 2 different subnets (first two Bytes): 185.132., 217.160., 2 different subnets (first three Bytes): 185.132.34., 217.160.80. A Excellent: Every Name Server IPv4-address starts with an unique Byte. A Info: IPv6-Subnet-list: 2 Name Servers with IPv6, 2 different subnets (first block): 2001:, 2607:, 2 different subnets (first two blocks): 2001:08d8:, 2607:f1c0:, 2 different subnets (first three blocks): 2001:08d8:00fe:, 2607:f1c0:00fe:, 2 different subnets (first four blocks): 2001:08d8:00fe:0053:, 2607:f1c0:00fe:0053: A Excellent: Every Name Server IPv6-address starts with an unique Hex-block 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 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. 4. 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 Good: All checked attribute values are enclosed in quotation marks (" or '). 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: 76404 milliseconds, 76.404 seconds