1. General Results, most used to calculate the result A name "onlinezdrav-test.eltc.ru" is subdomain, public suffix is ".ru", top-level-domain is ".ru", top-level-domain-type is "country-code", Country is Russian Federation (the), tld-manager is "Coordination Center for TLD RU", num .ru-domains preloaded: 1928 (complete: 175327) A good: No asked Authoritative Name Server had a timeout HSTS-Preload-Status: unknown. Domain never included in the Preload-list. Check https://hstspreload.org/ to learn some basics about the Google-Preload-List. Y onlinezdrav-test.eltc.ru 10.102.250.217 Warning: Private ip address found. No connection possible. There are two types of ip addresses: Worldwide unique, global addresses and private addresses. If you want that other users connect your domain, your domain must have minimal one A- (ipv4) or AAAA- (ipv6) entry with a global ip address. Check https://en.wikipedia.org/wiki/Private_network to understand the details: 10.0.0.0 to 10.255.255.255: Class A - one private net with 16.777.216 adresses Y www.onlinezdrav-test.eltc.ru 10.102.250.217 Warning: Private ip address found. No connection possible. There are two types of ip addresses: Worldwide unique, global addresses and private addresses. If you want that other users connect your domain, your domain must have minimal one A- (ipv4) or AAAA- (ipv6) entry with a global ip address. Check https://en.wikipedia.org/wiki/Private_network to understand the details: 10.0.0.0 to 10.255.255.255: Class A - one private net with 16.777.216 adresses 2. 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.ns.eltc.ru (212.75.210.80), ns2.eltc.ru (212.75.211.5) 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:: 3 different Name Servers found: eltc.ru, ns.eltc.ru, ns2.eltc.ru, 2 Name Servers included in Delegation: ns.eltc.ru, ns2.eltc.ru, 3 Name Servers included in 3 Zone definitions: eltc.ru, ns.eltc.ru, ns2.eltc.ru, 2 Name Servers listed in SOA.Primary: eltc.ru, ns.eltc.ru. Error: Different SOA.Primary Name Servers found, different SOA Definitions.: eltc.ru,ns.eltc.ru. Error: SOA.Primary Name Server not included in the delegation set.: eltc.ru,ns.eltc.ru. X Fatal: Inconsistency 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.: ns2.eltc.ru (212.75.211.5): Delegation: ns.eltc.ru, ns2.eltc.ru, Zone: eltc.ru. Name Servers defined in Delegation, missing in Zone: ns.eltc.ru, ns2.eltc.ru.Name Servers defined in Zone, missing in Delegation: eltc.ru. A Good: All Name Server Domain Names have a Public Suffix. Error: Name Server Domain Names with Public Suffix and without ip address found.: 1 Name Servers without ipv4 and ipv6: 1 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: ru A Good: Name Servers with different domain names found.: 2 different Domains found Warning: All Name Servers from the same Country / IP location.: 2 Name Servers, 1 Countries: RU A Info: Ipv4-Subnet-list: 2 Name Servers, 1 different subnets (first Byte): 212., 1 different subnets (first two Bytes): 212.75., 2 different subnets (first three Bytes): 212.75.210., 212.75.211. A Good: Name Server IPv4-addresses from different subnet found: A Good: Nameserver supports TCP connections: 2 good Nameserver A Good: Nameserver supports Echo Capitalization: 2 good Nameserver A Good: Nameserver supports EDNS with max. 512 Byte Udp payload, message is smaller: 2 good Nameserver Nameserver doesn't pass all EDNS-Checks: eltc.ru: 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: eltc.ru: 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: eltc.ru: 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. X Fatal error: Nameservers with different SOA Serial Numbers 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: 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: 64980 milliseconds, 64.980 seconds