1. General Results, most used to calculate the result A name "bbb.km.uz" is subdomain, public suffix is ".uz", top-level-domain is ".uz", top-level-domain-type is "country-code", Country is Uzbekistan, tld-manager is "Single Integrator for Creation and Support of State Information Systems UZINFOCOM", num .uz-domains preloaded: 18 (complete: 142558) 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 HSTS-Preload-Status: unknown. Domain never included in the Preload-list. Check https://hstspreload.org/ to learn some basics about the Google-Preload-List. X Fatal error: Nameserver doesn't support TCP connection: rdns2.ahost.uz / 116.202.82.237: NXDOMAIN 2. DNS- and NameServer - Checks A A A Info:: 0 different Name Servers found: , 0 Name Servers included in Delegation: , 0 Name Servers included in 0 Zone definitions: , 0 Name Servers listed in SOA.Primary: . A Good: Nameserver supports Echo Capitalization: 1 good Nameserver X Nameserver Timeout checking Echo Capitalization: ns.uz A Good: Nameserver supports EDNS with max. 512 Byte Udp payload, message is smaller: 1 good Nameserver X Nameserver Timeout checking EDNS512: ns.uz Nameserver doesn't pass all EDNS-Checks: ns.uz: OP100: ok. FLAGS: ok. V1: ok. V1OP100: ok. V1FLAGS: ok. DNSSEC: ok. V1DNSSEC: ok. NSID: ok. COOKIE: ok. CLIENTSUBNET: ok. Nameserver doesn't pass all EDNS-Checks: ns5.uz: OP100: ok. FLAGS: ok. V1: ok. V1OP100: ok. V1FLAGS: ok. DNSSEC: ok. V1DNSSEC: ok. NSID: ok. COOKIE: ok. CLIENTSUBNET: ok. Nameserver doesn't pass all EDNS-Checks: rdns1.ahost.uz: 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: rdns1.ahost.uz: 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 Info: Creating a Letsencrypt certificate with that domain name isn't possible. To create a certificate you need a registered, worldwide unique domain name. The domain name ends with a public suffix, that's good (not Grade Z). But the domain isn't registered. If you want a certificate with that domain name, you have to proof that you are the domain owner. Trouble creating a certificate? Use https://community.letsencrypt.org/ to ask. 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: 131517 milliseconds, 131.517 seconds