1. General Results, most used to calculate the result A name "traefik.kdoan.duckdns.org" is subdomain, public suffix is ".duckdns.org", top-level-domain is ".org", top-level-domain-type is "generic", tld-manager is "Public Interest Registry (PIR)", num .org-domains preloaded: 7605 (complete: 221801) A Good: All ip addresses are public addresses Warning: Only one ip address found: traefik.kdoan.duckdns.org has only one ip address. Warning: Only one ip address found: www.traefik.kdoan.duckdns.org 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: traefik.kdoan.duckdns.org has no ipv6 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: www.traefik.kdoan.duckdns.org has no ipv6 address. 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) B https://traefik.kdoan.duckdns.org/ 73.109.213.171 Missing HSTS-Header B https://www.traefik.kdoan.duckdns.org/ 73.109.213.171 Missing HSTS-Header C Error - no version with Http-Status 200 H Fatal error: No https - result with http-status 200, no encryption M http://traefik.kdoan.duckdns.org/ 73.109.213.171 Misconfiguration - main pages should never send http status 400 - 499 M http://www.traefik.kdoan.duckdns.org/ 73.109.213.171 Misconfiguration - main pages should never send http status 400 - 499 M https://traefik.kdoan.duckdns.org/ 73.109.213.171 Misconfiguration - main pages should never send http status 400 - 499 M https://www.traefik.kdoan.duckdns.org/ 73.109.213.171 Misconfiguration - main pages should never send http status 400 - 499 M https://73.109.213.171/ 73.109.213.171 Misconfiguration - main pages should never send http status 400 - 499 N https://traefik.kdoan.duckdns.org/ 73.109.213.171 Error - Certificate isn't trusted, RemoteCertificateNameMismatch, RemoteCertificateChainErrors N https://www.traefik.kdoan.duckdns.org/ 73.109.213.171 Error - Certificate isn't trusted, RemoteCertificateNameMismatch, RemoteCertificateChainErrors N https://73.109.213.171/ 73.109.213.171 Error - Certificate isn't trusted, RemoteCertificateNameMismatch, RemoteCertificateChainErrors O traefik.kdoan.duckdns.org / 73.109.213.171 / 443 Old connection: Cipher Suites without Forward Secrecy (FS) found. Remove all of these Cipher Suites, use only Cipher Suites with Forward Secrecy: Starting with ECDHE- or DHE - the last "E" says: "ephemeral". Or use Tls.1.3, then all Cipher Suites use FS. 4 Cipher Suites without Forward Secrecy found O www.traefik.kdoan.duckdns.org / 73.109.213.171 / 443 Old connection: Cipher Suites without Forward Secrecy (FS) found. Remove all of these Cipher Suites, use only Cipher Suites with Forward Secrecy: Starting with ECDHE- or DHE - the last "E" says: "ephemeral". Or use Tls.1.3, then all Cipher Suites use FS. 4 Cipher Suites without Forward Secrecy found X Fatal error: Nameserver doesn't support TCP connection: ns1.duckdns.org: Timeout 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: 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: 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: 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: 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: Timeout X Fatal error: Nameserver doesn't support TCP connection: ns6.duckdns.org / 3.97.58.28: Timeout X Fatal error: Nameserver doesn't support TCP connection: ns7.duckdns.org: Timeout X Fatal error: Nameserver doesn't support TCP connection: ns7.duckdns.org / 15.223.21.81: Timeout X Fatal error: Nameserver doesn't support TCP connection: ns8.duckdns.org: Timeout X Fatal error: Nameserver doesn't support TCP connection: ns8.duckdns.org / 15.223.106.16: Timeout X Fatal error: Nameserver doesn't support TCP connection: ns9.duckdns.org: Timeout X Fatal error: Nameserver doesn't support TCP connection: ns9.duckdns.org / 15.222.19.97: Timeout Info: Checking all ip addresses of that domain without sending the hostname only one certificate found. Checking all ip addresses and sending the hostname only one certificate found. Both certificates are the same. So that domain doesn't require Server Name Indication (SNI), it's the primary certificate of that set of ip addresses.: Domain traefik.kdoan.duckdns.org, 1 ip addresses, 1 different http results. Info: Checking all ip addresses of that domain without sending the hostname only one certificate found. Checking all ip addresses and sending the hostname only one certificate found. Both certificates are the same. So that domain doesn't require Server Name Indication (SNI), it's the primary certificate of that set of ip addresses.: Domain www.traefik.kdoan.duckdns.org, 1 ip addresses, 1 different http results. 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.traefik.kdoan.duckdns.org 2. Header-Checks (alpha, started 2022-10-23, may be buggy / incomplete) A traefik.kdoan.duckdns.org 73.109.213.171 X-Content-Type-Options Ok: Header without syntax errors found: nosniff A www.traefik.kdoan.duckdns.org 73.109.213.171 X-Content-Type-Options Ok: Header without syntax errors found: nosniff F traefik.kdoan.duckdns.org 73.109.213.171 Content-Security-Policy Critical: Missing Header: F traefik.kdoan.duckdns.org 73.109.213.171 Referrer-Policy Critical: Missing Header: F traefik.kdoan.duckdns.org 73.109.213.171 Permissions-Policy Critical: Missing Header: F www.traefik.kdoan.duckdns.org 73.109.213.171 Content-Security-Policy Critical: Missing Header: F www.traefik.kdoan.duckdns.org 73.109.213.171 Referrer-Policy Critical: Missing Header: F www.traefik.kdoan.duckdns.org 73.109.213.171 Permissions-Policy Critical: Missing Header: 3. DNS- and NameServer - Checks A Info:: 2 Root-climbing DNS Queries required to find all IPv4- and IPv6-Addresses of 2 Name Servers. A Info:: 2 Queries complete, 2 with IPv6, 0 with IPv4. A Good: All DNS Queries done via IPv6. A Good: Some ip addresses of name servers found with the minimum of two DNS Queries. One to find the TLD-Zone, one to ask the TLD-Zone.ns4.duckdns.org (3.97.51.116), ns6.duckdns.org (3.97.58.28) A Good (1 - 3.0):: An average of 1.0 queries per domain name server required to find all ip addresses of all name servers. A Info:: 9 different Name Servers found: ns1.duckdns.org, ns2.duckdns.org, ns3.duckdns.org, ns4.duckdns.org, ns5.duckdns.org, ns6.duckdns.org, ns7.duckdns.org, ns8.duckdns.org, ns9.duckdns.org, 9 Name Servers included in Delegation: ns1.duckdns.org, ns2.duckdns.org, ns3.duckdns.org, ns4.duckdns.org, ns5.duckdns.org, ns6.duckdns.org, ns7.duckdns.org, ns8.duckdns.org, ns9.duckdns.org, 0 Name Servers included in 1 Zone definitions: , 1 Name Servers listed in SOA.Primary: ns1.duckdns.org. A Good: Only one SOA.Primary Name Server found.: ns1.duckdns.org. A Good: SOA.Primary Name Server included in the delegation set.: ns1.duckdns.org. A Good: All Name Server Domain Names have a Public Suffix. Error: Name Server Domain Names with Public Suffix and without ip address found.: 7 Name Servers without ipv4 and ipv6: 7 A Good: Minimal 2 different name servers (public suffix and public ip address) found: 2 different Name Servers found Warning: No Name Server IPv6 address found. IPv6 is the future, so your name servers should be visible via IPv6.: 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: duckdns.org 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: Warning: All Name Servers from the same Country / IP location.: 2 Name Servers, 1 Countries: CA A Info: Ipv4-Subnet-list: 2 Name Servers, 1 different subnets (first Byte): 3., 1 different subnets (first two Bytes): 3.97., 2 different subnets (first three Bytes): 3.97.51., 3.97.58. A Good: Name Server IPv4-addresses from different subnet found: X Nameserver Timeout checking Echo Capitalization: ns2.duckdns.org X Nameserver Timeout checking Echo Capitalization: ns4.duckdns.org / 3.97.51.116 X Nameserver Timeout checking Echo Capitalization: ns6.duckdns.org / 3.97.58.28 X Nameserver Timeout checking Echo Capitalization: ns8.duckdns.org X Nameserver Timeout checking EDNS512: ns2.duckdns.org / 35.182.183.211 X Nameserver Timeout checking EDNS512: ns4.duckdns.org / 3.97.51.116 X Nameserver Timeout checking EDNS512: ns5.duckdns.org / 99.79.16.64 X Nameserver Timeout checking EDNS512: ns6.duckdns.org / 3.97.58.28 X Nameserver Timeout checking EDNS512: ns8.duckdns.org Nameserver doesn't pass all EDNS-Checks: ns1.duckdns.org: 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. Nameserver doesn't pass all EDNS-Checks: ns1.duckdns.org: 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: fatal timeout. 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: 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: OP100: fatal timeout. FLAGS: fatal timeout. V1: fatal timeout. V1OP100: fatal timeout. V1FLAGS: fatal timeout. DNSSEC: fatal timeout. V1DNSSEC: fatal timeout. NSID: ok. COOKIE: fatal timeout. CLIENTSUBNET: fatal timeout. 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: 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: 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. 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: 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: ns4.duckdns.org / 3.97.51.116: OP100: fatal timeout. FLAGS: fatal timeout. V1: fatal timeout. V1OP100: fatal timeout. V1FLAGS: fatal timeout. DNSSEC: fatal timeout. V1DNSSEC: fatal timeout. NSID: ok. COOKIE: fatal timeout. CLIENTSUBNET: fatal timeout. Nameserver doesn't pass all EDNS-Checks: ns5.duckdns.org: 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. Nameserver doesn't pass all EDNS-Checks: ns5.duckdns.org: 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: fatal timeout. V1: fatal timeout. V1OP100: fatal timeout. V1FLAGS: fatal timeout. DNSSEC: fatal timeout. V1DNSSEC: fatal timeout. NSID: fatal timeout. COOKIE: fatal timeout. CLIENTSUBNET: fatal timeout. Nameserver doesn't pass all EDNS-Checks: ns6.duckdns.org: 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: fatal timeout. FLAGS: fatal timeout. V1: fatal timeout. V1OP100: fatal timeout. V1FLAGS: fatal timeout. DNSSEC: fatal timeout. V1DNSSEC: fatal timeout. NSID: fatal timeout. COOKIE: fatal timeout. CLIENTSUBNET: fatal timeout. Nameserver doesn't pass all EDNS-Checks: ns6.duckdns.org / 3.97.58.28: OP100: fatal timeout. FLAGS: fatal timeout. V1: fatal timeout. V1OP100: fatal timeout. V1FLAGS: fatal timeout. DNSSEC: fatal timeout. V1DNSSEC: fatal timeout. NSID: fatal timeout. COOKIE: fatal timeout. CLIENTSUBNET: fatal timeout. Nameserver doesn't pass all EDNS-Checks: ns7.duckdns.org: 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. Nameserver doesn't pass all EDNS-Checks: ns7.duckdns.org: 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. Nameserver doesn't pass all EDNS-Checks: ns7.duckdns.org: 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: ns7.duckdns.org / 15.223.21.81: 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: ns8.duckdns.org: 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. Nameserver doesn't pass all EDNS-Checks: ns8.duckdns.org: 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: ns8.duckdns.org: OP100: fatal timeout. FLAGS: fatal timeout. V1: fatal timeout. V1OP100: fatal timeout. V1FLAGS: fatal timeout. DNSSEC: fatal timeout. V1DNSSEC: fatal timeout. NSID: fatal timeout. COOKIE: fatal timeout. CLIENTSUBNET: fatal timeout. Nameserver doesn't pass all EDNS-Checks: ns8.duckdns.org / 15.223.106.16: 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: ns9.duckdns.org: 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: ns9.duckdns.org: 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. Nameserver doesn't pass all EDNS-Checks: ns9.duckdns.org / 15.222.19.97: 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: ns9.duckdns.org / 15.222.19.97: 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. 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 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 https://traefik.kdoan.duckdns.org/ 73.109.213.171 5.293 seconds Warning: 404 needs more then one second https://www.traefik.kdoan.duckdns.org/ 73.109.213.171 5.273 seconds Warning: 404 needs more then one second https://73.109.213.171/ 73.109.213.171 5.260 seconds Warning: 404 needs more then one second A Duration: 3192270 milliseconds, 3192.270 seconds