1. General Results, most used to calculate the result A name "tokyo.cs.ait.ac.th" is subdomain, public suffix is ".ac.th", top-level-domain is ".th", top-level-domain-type is "country-code", Country is Thailand, tld-manager is "Thai Network Information Center Foundation", num .th-domains preloaded: 88 (complete: 221801) A Good: All ip addresses are public addresses Warning: Only one ip address found: tokyo.cs.ait.ac.th 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: tokyo.cs.ait.ac.th 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 https://tokyo.cs.ait.ac.th/hub/ https://tokyo.cs.ait.ac.th/hub/login?next=%2Fhub%2F Correct redirect https to https A https://tokyo.cs.ait.ac.th/ 192.41.170.86 https://tokyo.cs.ait.ac.th/hub/ Correct redirect https to https A https://192.41.170.86/ 192.41.170.86 https://tokyo.cs.ait.ac.th/hub/ Correct redirect https to https A Good: destination is https A Good - only one version with Http-Status 200 A Good: one preferred version: non-www is preferred 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):0 complete Content-Type - header (1 urls) https://tokyo.cs.ait.ac.th/hub/login?next=%2Fhub%2F Url with incomplete Content-Type - header - missing charset B https://tokyo.cs.ait.ac.th/hub/ Missing HSTS-Header B https://tokyo.cs.ait.ac.th/ 192.41.170.86 Missing HSTS-Header B https://tokyo.cs.ait.ac.th/hub/login?next=%2Fhub%2F Missing HSTS-Header I https://tokyo.cs.ait.ac.th/hub/login?next=%2Fhub%2F Content problems or problems with resources included - http links, files doesn't exist, different Content-Type definitions. Check the Html-Content - Part. N https://192.41.170.86/ 192.41.170.86 https://tokyo.cs.ait.ac.th/hub/ Error - Certificate isn't trusted, RemoteCertificateNameMismatch 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 tokyo.cs.ait.ac.th, 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.tokyo.cs.ait.ac.th 2. Header-Checks (alpha, started 2022-10-23, may be buggy / incomplete) A tokyo.cs.ait.ac.th Content-Security-Policy Ok: Header without syntax errors found: frame-ancestors 'self'; report-uri /hub/security/csp-report B Info: Header-Element is deprecated. report-uri /hub/security/csp-report F Bad: Missing default-src directive. A default-src directive is used if one of the specialized fetch directives (child-src, connect-src, font-src, frame-src, img-src, manifest-src, media-src, object-src, prefetch-src, script-src, style-src, worker-src) isn't defined. Missing default-src, all sources are allowed, that's bad. A default-src with 'none' or 'self' blocks that. E Bad: No form-action directive found. Use one to limit the form - action - destinations. form-action is a navigation-directive, so default-src isn't used. A Good: frame-ancestors directive found. That limits pages who are allowed to use this page in a frame / iframe / object / embed / applet. frame-ancestors is a navigation-directive, so default-src isn't used. E Bad: No base-uri directive found. Use one to limit the URLs which can be used in a document's <base> element. Because it's a document directive, default-src isn't used, so an own directive is required. F Critical: No object-src and no default-src as fallback defined. So object / embed / applet can load every resource. That's fatal. F Critical: No script-src and no default-src as fallback defined. So scripts are unlimited. That's fatal. F tokyo.cs.ait.ac.th X-Content-Type-Options Critical: Missing Header: F tokyo.cs.ait.ac.th Referrer-Policy Critical: Missing Header: F tokyo.cs.ait.ac.th Permissions-Policy Critical: Missing Header: 3. DNS- and NameServer - Checks A Info:: 5 Root-climbing DNS Queries required to find all IPv4- and IPv6-Addresses of 2 Name Servers. A Info:: 5 Queries complete, 3 with IPv6, 2 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. 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.inetserv.ait.ac.th (203.159.0.1) A Good (1 - 3.0):: An average of 2.5 queries per domain name server required to find all ip addresses of all name servers. A Info:: 3 different Name Servers found: dns.cs.ait.ac.th, inetserv.ait.ac.th, ns.thnic.net, 3 Name Servers included in Delegation: dns.cs.ait.ac.th, inetserv.ait.ac.th, ns.thnic.net, 3 Name Servers included in 1 Zone definitions: dns.cs.ait.ac.th, inetserv.ait.ac.th, ns.thnic.net, 1 Name Servers listed in SOA.Primary: dns.cs.ait.ac.th. A Good: Only one SOA.Primary Name Server found.: dns.cs.ait.ac.th. A Good: SOA.Primary Name Server included in the delegation set.: dns.cs.ait.ac.th. 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: dns.cs.ait.ac.th, inetserv.ait.ac.th, ns.thnic.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: 3 different Name Servers found Warning: No Name Server IPv6 address found. IPv6 is the future, so your name servers should be visible via IPv6.: 3 different Name Servers found A Good: Name servers with different Top Level Domains / Public Suffix List entries found: 3 Name Servers, 2 Top Level Domains: net, ac.th A Good: Name Servers with different domain names found.: 2 different Domains found Warning: All Name Servers from the same Country / IP location.: 3 Name Servers, 1 Countries: TH A Info: Ipv4-Subnet-list: 3 Name Servers, 3 different subnets (first Byte): 192., 202., 203., 3 different subnets (first two Bytes): 192.41., 202.28., 203.159., 3 different subnets (first three Bytes): 192.41.170., 202.28.0., 203.159.0. A Excellent: Every Name Server IPv4-address starts with an unique Byte. A Good: Nameserver supports TCP connections: 1 good Nameserver A Good: Nameserver supports Echo Capitalization: 1 good Nameserver A Good: Nameserver supports EDNS with max. 512 Byte Udp payload, message is smaller: 1 good Nameserver A Good: Nameserver has passed 10 EDNS-Checks (OP100, FLAGS, V1, V1OP100, V1FLAGS, DNSSEC, V1DNSSEC, NSID, COOKIE, CLIENTSUBNET): 1 good Nameserver Nameserver doesn't pass all EDNS-Checks: dns.cs.ait.ac.th: 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 A Good: CAA entries found, creating certificate is limited: ait.ac.th is allowed to create certificates A Good: CAA entries found, creating certificate is limited: cs.ait.ac.th is allowed to create certificates A Good: CAA entries found, creating certificate is limited: letsencrypt.org is allowed to create certificates Warning: Unknown CAA found: ait.ac.th isn't defined. Unknown entry. May be wrong written, may be not longer valid. May be a missing entry in this tool. Warning: Unknown CAA found: cs.ait.ac.th isn't defined. Unknown entry. May be wrong written, may be not longer valid. May be a missing entry in this tool. 4. Content- and Performance-critical Checks http://tokyo.cs.ait.ac.th/.well-known/acme-challenge/check-your-website-dot-server-daten-dot-de 192.41.170.86 Fatal: Check of /.well-known/acme-challenge/random-filename is blocked, http connection error. Creating a Letsencrypt certificate via http-01 challenge can't work. You need a running webserver (http) and an open port 80. If it's a home server + ipv4, perhaps a correct port forwarding port 80 extern ⇒ working port intern is required. Port 80 / http can redirect to another domain port 80 or port 443, but not other ports. If it's a home server, perhaps your ISP blocks port 80. Then you may use the dns-01 challenge. Trouble creating a certificate? Use https://community.letsencrypt.org/ to ask. https://tokyo.cs.ait.ac.th/hub/login?next=%2Fhub%2F Warning: https result with status 200 and size greater then 1024 Bytes without GZip found. Add GZip support so the html content is compressed. https://tokyo.cs.ait.ac.th/hub/login?next=%2Fhub%2F Warning: Https + http status 200 + Inline CSS / JavaScript found. Don't use inline CSS / JavaScript. These are compiled and re-used ressources, save these with a long Cache-Control max-age - header. https://tokyo.cs.ait.ac.th/hub/login?next=%2Fhub%2F Warning: Https result with status 200 found, Html-Content is too big. Should be max. 110 %. May contain inline CSS / JavaScript, too much comments or white space. Re-used ressources - create files with a long Cache-Control max-age header. Remove comments and white space. https://tokyo.cs.ait.ac.th/hub/login?next=%2Fhub%2F Warning: Https connections (Standard Port 443) found without support of the http/2 protocol via ALPN. Http/2 is the new Http-Version (old: http 1.1) with some important new features. Update your server software so http/2 is available. Only one TCP-connection per Server (that's a performance boost), Header-Compression and Server Pushs are available. Domain Sharding and Inline-CSS/Javascript shouldn't used with http/2. https://tokyo.cs.ait.ac.th/hub/login?next=%2Fhub%2F Critical: Some script Elements (type text/javascript) with a src-Attribute don't have a defer / async - Attribute. Loading and executing these JavaScripts blocks parsing and rendering the Html-Output. That's bad if your site is large or the connection is slow / mobile usage. Use "async" if the js file has only functions (so nothing is executed after parsing the file) or is independend. Use "defer" if the order of the scripts is important. All "defer" scripts are executed before the DOMContentLoaded event is fired. Check https://developer.mozilla.org/en-US/docs/Web/HTML/Element/script to see some details.: 3 script elements without defer/async. Warning: CSS / JavaScript found without GZip support. Send these ressources with GZip. 4 external CSS / JavaScript files without GZip found - 0 with GZip, 4 complete Warning: CSS / JavaScript files with a missing or too short Cache-Control header found. Browsers should cache and re-use these files. 4 external CSS / JavaScript files without Cache-Control-Header, 0 with Cache-Control, but no max-age, 0 with Cache-Control max-age too short (minimum 7 days), 0 with Cache-Control long enough, 4 complete. Warning: Images with a missing or too short Cache-Control header found. Browsers should cache and re-use these files. 1 image files without Cache-Control-Header, 0 with Cache-Control, but no max-age, 0 with Cache-Control max-age too short (minimum 7 days), 0 with Cache-Control long enough, 1 complete. A Good: All checked attribute values are enclosed in quotation marks (" or '). A Good: All img-elements have a valid alt-attribute.: 1 img-elements found. 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: 364396 milliseconds, 364.396 seconds