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DNS-problem - authoritative Nameserver refused, not defined or timeout

Checked:
08.11.2025 16:08:23

Older results

No older results found

1. IP-Addresses

Host	Type	IP-Address	is auth.	∑ Queries	∑ Timeout
duynh.io.vn	A	123.21.170.80 Bình Tân/Tiền Giang/Vietnam (VN) - VietNam Post and Telecom Corporation No Hostname found	yes	2	0
	AAAA		yes
www.duynh.io.vn	CNAME	duynh.io.vn	yes	1	0
	A	123.21.170.80 Bình Tân/Tiền Giang/Vietnam (VN) - VietNam Post and Telecom Corporation No Hostname found	yes
*.duynh.io.vn	A	Name Error	yes
	AAAA	Name Error	yes
	CNAME	Name Error	yes

2. DNSSEC

Zone (*)	DNSSEC - Informations

Zone: (root)
(root)	1 DS RR published


	DS with Algorithm 8, KeyTag 20326, DigestType 2 and Digest 4G1EuAuPHTmpXAsNfGXQhFjogECbvGg0VxBCN8f47I0=


	• Status: Valid because published


	3 DNSKEY RR found


	Public Key with Algorithm 8, KeyTag 20326, Flags 257 (SEP = Secure Entry Point)


	Public Key with Algorithm 8, KeyTag 38696, Flags 257 (SEP = Secure Entry Point)


	Public Key with Algorithm 8, KeyTag 61809, Flags 256


	1 RRSIG RR to validate DNSKEY RR found


	RRSIG-Owner (root), Algorithm: 8, 0 Labels, original TTL: 172800 sec, Signature-expiration: 21.11.2025, 00:00:00 +, Signature-Inception: 31.10.2025, 00:00:00 +, KeyTag 20326, Signer-Name: (root)


	• Status: Good - Algorithmus 8 and DNSKEY with KeyTag 20326 used to validate the DNSKEY RRSet


	• Status: Valid Chain of trust. Parent-DS with Algorithm 8, KeyTag 20326, DigestType 2 and Digest "4G1EuAuPHTmpXAsNfGXQhFjogECbvGg0VxBCN8f47I0=" validates local Key with the same values, Key ist Secure Entry Point (SEP) of the zone

Zone: vn
vn	2 DS RR in the parent zone found


	DS with Algorithm 8, KeyTag 16196, DigestType 2 and Digest y2jFOEEEsx4dnLwcRfhhqSzanYEhr+dvmol4UnmD/Zk=


	DS with Algorithm 8, KeyTag 16196, DigestType 4 and Digest J2ZD9e9DoGECd8BsxSYQVnKEULFYSzT20Z9MW9ndHe/y1dPLgFuGcYseB3hoKv6R


	1 RRSIG RR to validate DS RR found


	RRSIG-Owner vn., Algorithm: 8, 1 Labels, original TTL: 86400 sec, Signature-expiration: 21.11.2025, 05:00:00 +, Signature-Inception: 08.11.2025, 04:00:00 +, KeyTag 61809, Signer-Name: (root)


	• Status: Good - Algorithmus 8 and DNSKEY with KeyTag 61809 used to validate the DS RRSet in the parent zone


	2 DNSKEY RR found


	Public Key with Algorithm 8, KeyTag 16196, Flags 257 (SEP = Secure Entry Point)


	Public Key with Algorithm 8, KeyTag 52956, Flags 256


	2 RRSIG RR to validate DNSKEY RR found


	RRSIG-Owner vn., Algorithm: 8, 1 Labels, original TTL: 43200 sec, Signature-expiration: 23.11.2025, 23:22:51 +, Signature-Inception: 24.10.2025, 22:55:58 +, KeyTag 16196, Signer-Name: vn


	RRSIG-Owner vn., Algorithm: 8, 1 Labels, original TTL: 43200 sec, Signature-expiration: 23.11.2025, 23:22:51 +, Signature-Inception: 24.10.2025, 22:55:58 +, KeyTag 52956, Signer-Name: vn


	• Status: Good - Algorithmus 8 and DNSKEY with KeyTag 16196 used to validate the DNSKEY RRSet


	• Status: Good - Algorithmus 8 and DNSKEY with KeyTag 52956 used to validate the DNSKEY RRSet


	• Status: Valid Chain of trust. Parent-DS with Algorithm 8, KeyTag 16196, DigestType 2 and Digest "y2jFOEEEsx4dnLwcRfhhqSzanYEhr+dvmol4UnmD/Zk=" validates local Key with the same values, Key ist Secure Entry Point (SEP) of the zone


	• Status: Valid Chain of trust. Parent-DS with Algorithm 8, KeyTag 16196, DigestType 4 and Digest "J2ZD9e9DoGECd8BsxSYQVnKEULFYSzT20Z9MW9ndHe/y1dPLgFuGcYseB3hoKv6R" validates local Key with the same values, Key ist Secure Entry Point (SEP) of the zone

Zone: io.vn
io.vn	2 DS RR in the parent zone found


	DS with Algorithm 8, KeyTag 56381, DigestType 2 and Digest KpPkwkq+OtliWYv42YIYbAVBC1YzXv5frjDS2eH6h10=


	DS with Algorithm 8, KeyTag 56381, DigestType 4 and Digest 6pCUxMlkGq9RPPKYMSFRpT0c26P6F9j3u6NGhCadQyWQ35S0PnhnVfu6yuNNDXse


	1 RRSIG RR to validate DS RR found


	RRSIG-Owner io.vn., Algorithm: 8, 2 Labels, original TTL: 43200 sec, Signature-expiration: 02.12.2025, 09:23:51 +, Signature-Inception: 02.11.2025, 09:03:22 +, KeyTag 52956, Signer-Name: vn


	• Status: Good - Algorithmus 8 and DNSKEY with KeyTag 52956 used to validate the DS RRSet in the parent zone


	2 DNSKEY RR found


	Public Key with Algorithm 8, KeyTag 56381, Flags 257 (SEP = Secure Entry Point)


	Public Key with Algorithm 8, KeyTag 63499, Flags 256


	2 RRSIG RR to validate DNSKEY RR found


	RRSIG-Owner io.vn., Algorithm: 8, 2 Labels, original TTL: 43200 sec, Signature-expiration: 23.11.2025, 23:30:42 +, Signature-Inception: 24.10.2025, 23:25:43 +, KeyTag 56381, Signer-Name: io.vn


	RRSIG-Owner io.vn., Algorithm: 8, 2 Labels, original TTL: 43200 sec, Signature-expiration: 23.11.2025, 23:30:42 +, Signature-Inception: 24.10.2025, 23:25:43 +, KeyTag 63499, Signer-Name: io.vn


	• Status: Good - Algorithmus 8 and DNSKEY with KeyTag 56381 used to validate the DNSKEY RRSet


	• Status: Good - Algorithmus 8 and DNSKEY with KeyTag 63499 used to validate the DNSKEY RRSet


	• Status: Valid Chain of trust. Parent-DS with Algorithm 8, KeyTag 56381, DigestType 2 and Digest "KpPkwkq+OtliWYv42YIYbAVBC1YzXv5frjDS2eH6h10=" validates local Key with the same values, Key ist Secure Entry Point (SEP) of the zone


	• Status: Valid Chain of trust. Parent-DS with Algorithm 8, KeyTag 56381, DigestType 4 and Digest "6pCUxMlkGq9RPPKYMSFRpT0c26P6F9j3u6NGhCadQyWQ35S0PnhnVfu6yuNNDXse" validates local Key with the same values, Key ist Secure Entry Point (SEP) of the zone

Zone: duynh.io.vn
duynh.io.vn	0 DS RR in the parent zone found


	DS-Query in the parent zone has a valid NSEC3 RR as result with the hashed query name "ud8lc77fsadta7lq1i7s568mv01m009t" between the hashed NSEC3-owner "u7efa82t3j99rjpc0su94jbk94uf80ua" and the hashed NextOwner "udt3k1ujvsealjnmaurlq7ldm7dls8rj". So the parent zone confirmes the not-existence of a DS RR. Bitmap: NS, DS, RRSIG Validated: RRSIG-Owner u7efa82t3j99rjpc0su94jbk94uf80ua.io.vn., Algorithm: 8, 3 Labels, original TTL: 5400 sec, Signature-expiration: 28.11.2025, 15:41:15 +, Signature-Inception: 29.10.2025, 15:20:12 +, KeyTag 63499, Signer-Name: io.vn


	DS-Query in the parent zone sends valid NSEC3 RR with the Hash "qbku1sg91rvsbegup59e0d4eocc05rpi" as Owner. That's the Hash of "io.vn" with the NextHashedOwnerName "qd9s5q5uhin28ig8dtk9d19l9ldd6jjn". So that domain name is the Closest Encloser of "duynh.io.vn". Opt-Out: True. Bitmap: NS, SOA, RRSIG, DNSKEY, NSEC3PARAM Validated: RRSIG-Owner qbku1sg91rvsbegup59e0d4eocc05rpi.io.vn., Algorithm: 8, 3 Labels, original TTL: 5400 sec, Signature-expiration: 27.11.2025, 01:58:56 +, Signature-Inception: 28.10.2025, 01:19:40 +, KeyTag 63499, Signer-Name: io.vn


	0 DNSKEY RR found




Zone: www.duynh.io.vn
www.duynh.io.vn	0 DS RR in the parent zone found

3. Name Servers

Domain	Nameserver	NS-IP
duynh.io.vn	• ns1.zonedns.vn	64.176.84.220 Singapore/South West/Singapore (SG) - The Constant Company, LLC	•
	•	2401:c080:1400:1cd4:5400:5ff:fe80:ec33 Singapore/South West/Singapore (SG) - The Constant Company, LLC	•
	T ns2.zonedns.vn	103.176.178.51 Láng Thượng/Hanoi/Vietnam (VN) - NINETECH
	•	2401:c080:1400:1cd4:5400:5ff:fe80:ec33 Singapore/South West/Singapore (SG) - The Constant Company, LLC	•
	• ns3.zonedns.vn	103.28.36.30 Ô Chợ Dừa/Hanoi/Vietnam (VN) - NhanHoa Software Company	•
	•	2001:df1:3200::15 Vinhomes Royal City/Hanoi/Vietnam (VN) - NhanHoa Software company	•
	X ns4.zonedns.vn	103.28.39.159 Ô Chợ Dừa/Hanoi/Vietnam (VN) - NhanHoa Software Company
	•	2001:df1:3200::15 Vinhomes Royal City/Hanoi/Vietnam (VN) - NhanHoa Software company	•
	• ns5.zonedns.vn
io.vn	• a.dns-servers.vn	194.0.1.18 Christchurch/England/United Kingdom (GB) - ICB plc Anycast (via NetConnex AS21396)	•
	•	2001:678:4::12 Frankfurt am Main/Hesse/Germany (DE) - Community DNS Limited	•
	• b.dns-servers.vn	203.119.73.105 Hai BàTrưng/Hanoi/Vietnam (VN) - VNNIC	•
	•	2001:dc8:1:2::105 Hanoi/Vietnam (VN) - Vietnam Internet network information center	•
	T c.dns-servers.vn	203.119.38.105 Hanoi/Vietnam (VN) - VNNIC	•
	•	2001:dc8:c000:7::105 Hanoi/Vietnam (VN) - Vietnam Internet Network Information Center	•
	• d.dns-servers.vn	203.119.44.105 Hai BàTrưng/Hanoi/Vietnam (VN) - VNNIC	•
	•	2001:dc8:8000:2::105 Hanoi/Vietnam (VN) - VNNIC	•
	• dns-master.vnnic.vn
	• e.dns-servers.vn	203.119.60.105 Hai BàTrưng/Hanoi/Vietnam (VN) - VNNIC	•
	•	2001:dc8:1000:2::105 Hanoi/Vietnam (VN) - Vietnam Internet network information center	•
	• f.dns-servers.vn	203.119.68.105 Hai BàTrưng/Hanoi/Vietnam (VN) - Vietnam Internet Network Information Center	•
	•	2001:dc8:d000:2::105 Hanoi/Vietnam (VN) - VNNIC	•
	X g.dns-servers.vn / 7.fra.pch	204.61.216.115 Montreal/Quebec/Canada (CA) - WoodyNet, Inc.
	•	2001:500:14:6115:ad::1 Montreal/Quebec/Canada (CA) - WoodyNet, Inc.	•
	• h.dns-servers.vn	202.47.142.105 Hanoi/Vietnam (VN) - Vietnam Internet Network Information Center	•
	•	2001:dc8:6000::105 Hanoi/Vietnam (VN) - VNNIC DNS Anycast	•
vn	• a.dns-servers.vn		•
	• b.dns-servers.vn		•
	• c.dns-servers.vn		•
	X d.dns-servers.vn
	• dns-master.vnnic.vn
	• e.dns-servers.vn		•
	• f.dns-servers.vn		•
	• g.dns-servers.vn / 4.fra.pch		•
	• h.dns-servers.vn		•

4. SOA-Entries

Domain:	vn
Zone-Name:
Primary:
Mail:
Serial:
Refresh:
Retry:
Expire:
TTL:
num Entries:	2

Domain:	vn
Zone-Name:	vn
Primary:	dns-master.vnnic.vn
Mail:	postmaster.vnnic.vn
Serial:	2030153556
Refresh:	3600
Retry:	1800
Expire:	604800
TTL:	5400
num Entries:	2

Domain:	vn
Zone-Name:	vn
Primary:	dns-master.vnnic.vn
Mail:	postmaster.vnnic.vn
Serial:	2030153557
Refresh:	3600
Retry:	1800
Expire:	604800
TTL:	5400
num Entries:	5

Domain:	io.vn
Zone-Name:
Primary:
Mail:
Serial:
Refresh:
Retry:
Expire:
TTL:
num Entries:	3

Domain:	io.vn
Zone-Name:	io.vn
Primary:	dns-master.vnnic.vn
Mail:	postmaster.vnnic.vn
Serial:	2023442737
Refresh:	3600
Retry:	1800
Expire:	604800
TTL:	5400
num Entries:	6

Domain:	io.vn
Zone-Name:	io.vn
Primary:	dns-master.vnnic.vn
Mail:	postmaster.vnnic.vn
Serial:	2023442740
Refresh:	3600
Retry:	1800
Expire:	604800
TTL:	5400
num Entries:	8

Domain:	duynh.io.vn
Zone-Name:
Primary:
Mail:
Serial:
Refresh:
Retry:
Expire:
TTL:
num Entries:	4

Domain:	duynh.io.vn
Zone-Name:	duynh.io.vn
Primary:	ns1.zonedns.vn
Mail:	root.duynh.io.vn
Serial:	2025110806
Refresh:	1200
Retry:	600
Expire:	1209600
TTL:	3600
num Entries:	5

5. Screenshots

No Screenshot listed, because no url-check with https + http status 200-299, 400-599 + not-ACME-check found.

6. Url-Checks

Domainname	Http-Status	Sec.	G
• http://duynh.io.vn/ 123.21.170.80	-14	10.030	T
Timeout - The operation has timed out.

• http://www.duynh.io.vn/ 123.21.170.80	-14	10.027	T
Timeout - The operation has timed out.

• https://duynh.io.vn/ 123.21.170.80	-14	10.030	T
Timeout - The operation has timed out.

• https://www.duynh.io.vn/ 123.21.170.80	-14	10.013	T
Timeout - The operation has timed out.

• http://duynh.io.vn/.well-known/acme-challenge/check-your-website-dot-server-daten-dot-de 123.21.170.80	-14	10.030	T
Timeout - The operation has timed out.
Visible Content:

• http://www.duynh.io.vn/.well-known/acme-challenge/check-your-website-dot-server-daten-dot-de 123.21.170.80	-14	10.047	T
Timeout - The operation has timed out.
Visible Content:

• https://123.21.170.80/ 123.21.170.80	-14	10.013	T
Timeout - The operation has timed out.

7. Comments

	1. General Results, most used to calculate the result
A	name "duynh.io.vn" is domain, public suffix is ".io.vn", top-level-domain is ".vn", top-level-domain-type is "country-code", Country is Viet Nam, tld-manager is "Ministry of Information and Communications of Socialist Republic of Viet Nam", num .vn-domains preloaded: 397 (complete: 276475)
A	Good: All ip addresses are public addresses
	Warning: Only one ip address found: duynh.io.vn has only one ip address.
	Warning: Only one ip address found: www.duynh.io.vn 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: duynh.io.vn 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.duynh.io.vn has no ipv6 address.
	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 isn't defined or has timeout
X	Fatal error: Nameserver doesn't support TCP connection: d.dns-servers.vn: Fatal error (-14). Details: Unable to read data from the transport connection: Ein Verbindungsversuch ist fehlgeschlagen, da die Gegenstelle nach einer bestimmten Zeitspanne nicht richtig reagiert hat, oder die hergestellte Verbindung war fehlerhaft, da der verbundene Host nicht reagiert hat.. - Ein Verbindungsversuch ist fehlgeschlagen, da die Gegenstelle nach einer bestimmten Zeitspanne nicht richtig reagiert hat, oder die hergestellte Verbindung war fehlerhaft, da der verbundene Host nicht reagiert hat
X	Fatal error: Nameserver doesn't support TCP connection: g.dns-servers.vn / 204.61.216.115: Fatal error (-14). Details: Unable to read data from the transport connection: Eine vorhandene Verbindung wurde vom Remotehost geschlossen.. - Eine vorhandene Verbindung wurde vom Remotehost geschlossen.
X	Fatal error: Nameserver doesn't support TCP connection: ns2.zonedns.vn / 103.176.178.51: Timeout
X	Fatal error: Nameserver doesn't support TCP connection: ns4.zonedns.vn / 103.28.39.159: Timeout
	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 duynh.io.vn, 1 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.duynh.io.vn, 1 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.duynh.io.vn
	2. Header-Checks
U			No https result with http status 2 or 4 (standard-check) found, no header checked.
	3. DNS- and NameServer - Checks
A	Info:: 13 Root-climbing DNS Queries required to find all IPv4- and IPv6-Addresses of 4 Name Servers.
A	Info:: 13 Queries complete, 5 with IPv6, 8 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 3.3 queries per domain name server required to find all ip addresses of all name servers.
A	Info:: 5 different Name Servers found: ns1.zonedns.vn, ns2.zonedns.vn, ns3.zonedns.vn, ns4.zonedns.vn, ns5.zonedns.vn, 5 Name Servers included in Delegation: ns1.zonedns.vn, ns2.zonedns.vn, ns3.zonedns.vn, ns4.zonedns.vn, ns5.zonedns.vn, 4 Name Servers included in 2 Zone definitions: ns1.zonedns.vn, ns2.zonedns.vn, ns3.zonedns.vn, ns4.zonedns.vn, 1 Name Servers listed in SOA.Primary: ns1.zonedns.vn.
A	Good: Only one SOA.Primary Name Server found.: ns1.zonedns.vn.
A	Good: SOA.Primary Name Server included in the delegation set.: ns1.zonedns.vn.
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. Read https://www.iana.org/help/nameserver-requirements and send it to your Name Server Hoster.: ns1.zonedns.vn (64.176.84.220): Delegation: ns1.zonedns.vn, ns2.zonedns.vn, ns3.zonedns.vn, ns4.zonedns.vn, ns5.zonedns.vn, Zone: ns1.zonedns.vn, ns2.zonedns.vn, ns3.zonedns.vn, ns4.zonedns.vn. Name Servers defined in Delegation, missing in Zone: ns5.zonedns.vn.
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. Read https://www.iana.org/help/nameserver-requirements and send it to your Name Server Hoster.: ns1.zonedns.vn (2401:c080:1400:1cd4:5400:5ff:fe80:ec33): Delegation: ns1.zonedns.vn, ns2.zonedns.vn, ns3.zonedns.vn, ns4.zonedns.vn, ns5.zonedns.vn, Zone: ns1.zonedns.vn, ns2.zonedns.vn, ns3.zonedns.vn, ns4.zonedns.vn. Name Servers defined in Delegation, missing in Zone: ns5.zonedns.vn.
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. Read https://www.iana.org/help/nameserver-requirements and send it to your Name Server Hoster.: ns2.zonedns.vn (103.176.178.51): Delegation: ns1.zonedns.vn, ns2.zonedns.vn, ns3.zonedns.vn, ns4.zonedns.vn, ns5.zonedns.vn, Zone: ns1.zonedns.vn, ns2.zonedns.vn, ns3.zonedns.vn, ns4.zonedns.vn. Name Servers defined in Delegation, missing in Zone: ns5.zonedns.vn.
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. Read https://www.iana.org/help/nameserver-requirements and send it to your Name Server Hoster.: ns2.zonedns.vn (2401:c080:1400:1cd4:5400:5ff:fe80:ec33): Delegation: ns1.zonedns.vn, ns2.zonedns.vn, ns3.zonedns.vn, ns4.zonedns.vn, ns5.zonedns.vn, Zone: ns1.zonedns.vn, ns2.zonedns.vn, ns3.zonedns.vn, ns4.zonedns.vn. Name Servers defined in Delegation, missing in Zone: ns5.zonedns.vn.
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. Read https://www.iana.org/help/nameserver-requirements and send it to your Name Server Hoster.: ns3.zonedns.vn (103.28.36.30): Delegation: ns1.zonedns.vn, ns2.zonedns.vn, ns3.zonedns.vn, ns4.zonedns.vn, ns5.zonedns.vn, Zone: ns1.zonedns.vn, ns2.zonedns.vn, ns3.zonedns.vn, ns4.zonedns.vn. Name Servers defined in Delegation, missing in Zone: ns5.zonedns.vn.
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. Read https://www.iana.org/help/nameserver-requirements and send it to your Name Server Hoster.: ns3.zonedns.vn (2001:df1:3200::15): Delegation: ns1.zonedns.vn, ns2.zonedns.vn, ns3.zonedns.vn, ns4.zonedns.vn, ns5.zonedns.vn, Zone: ns1.zonedns.vn, ns2.zonedns.vn, ns3.zonedns.vn, ns4.zonedns.vn. Name Servers defined in Delegation, missing in Zone: ns5.zonedns.vn.
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. Read https://www.iana.org/help/nameserver-requirements and send it to your Name Server Hoster.: ns4.zonedns.vn (103.28.39.159): Delegation: ns1.zonedns.vn, ns2.zonedns.vn, ns3.zonedns.vn, ns4.zonedns.vn, ns5.zonedns.vn, Zone: ns1.zonedns.vn, ns2.zonedns.vn, ns3.zonedns.vn, ns4.zonedns.vn. Name Servers defined in Delegation, missing in Zone: ns5.zonedns.vn.
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. Read https://www.iana.org/help/nameserver-requirements and send it to your Name Server Hoster.: ns4.zonedns.vn (2001:df1:3200::15): Delegation: ns1.zonedns.vn, ns2.zonedns.vn, ns3.zonedns.vn, ns4.zonedns.vn, ns5.zonedns.vn, Zone: ns1.zonedns.vn, ns2.zonedns.vn, ns3.zonedns.vn, ns4.zonedns.vn. Name Servers defined in Delegation, missing in Zone: ns5.zonedns.vn.
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: 4 different Name Servers found
A	Good: All name servers have ipv4- and ipv6-addresses.: 4 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.: 4 Name Servers, 1 Top Level Domain: vn
	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: zonedns.vn
A	Good: Name servers with different Country locations found: 4 Name Servers, 2 Countries: SG, VN
A	Info: Ipv4-Subnet-list: 4 Name Servers, 2 different subnets (first Byte): 103., 64., 3 different subnets (first two Bytes): 103.176., 103.28., 64.176., 4 different subnets (first three Bytes): 103.176.178., 103.28.36., 103.28.39., 64.176.84.
A	Good: Name Server IPv4-addresses from different subnet found:
A	Info: IPv6-Subnet-list: 4 Name Servers with IPv6, 2 different subnets (first block): 2001:, 2401:, 2 different subnets (first two blocks): 2001:0df1:, 2401:c080:, 2 different subnets (first three blocks): 2001:0df1:3200:, 2401:c080:1400:, 2 different subnets (first four blocks): 2001:0df1:3200:0000:, 2401:c080:1400:1cd4:
A	Good: Name Server IPv6 addresses from different subnets found.
X	Nameserver Timeout checking Echo Capitalization: c.dns-servers.vn / 203.119.38.105
X	Nameserver Timeout checking Echo Capitalization: ns2.zonedns.vn / 103.176.178.51
X	Nameserver Timeout checking EDNS512: ns2.zonedns.vn / 103.176.178.51
	Nameserver doesn't pass all EDNS-Checks: c.dns-servers.vn: 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: c.dns-servers.vn / 203.119.38.105: OP100: ok. FLAGS: ok. V1: ok. V1OP100: ok. V1FLAGS: ok. DNSSEC: fatal timeout. V1DNSSEC: ok. NSID: fatal timeout. COOKIE: ok. CLIENTSUBNET: ok.
	Nameserver doesn't pass all EDNS-Checks: d.dns-servers.vn / 2001:dc8:8000:2::105: OP100: ok. FLAGS: ok. V1: ok. V1OP100: fatal timeout. V1FLAGS: ok. DNSSEC: ok. V1DNSSEC: ok. NSID: ok. COOKIE: ok. CLIENTSUBNET: ok.
	Nameserver doesn't pass all EDNS-Checks: dns-master.vnnic.vn: 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: dns-master.vnnic.vn: 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: f.dns-servers.vn / 2001:dc8:d000:2::105: OP100: ok. FLAGS: ok. V1: ok. V1OP100: ok. V1FLAGS: ok. DNSSEC: ok. V1DNSSEC: ok. NSID: ok. COOKIE: fatal timeout. CLIENTSUBNET: ok.
	Nameserver doesn't pass all EDNS-Checks: h.dns-servers.vn: 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: ns1.zonedns.vn / 2401:c080:1400:1cd4:5400:5ff:fe80:ec33: OP100: ok. FLAGS: ok. V1: ok. V1OP100: ok. V1FLAGS: fatal timeout. DNSSEC: ok. V1DNSSEC: ok. NSID: ok. COOKIE: ok. CLIENTSUBNET: ok.
	Nameserver doesn't pass all EDNS-Checks: ns2.zonedns.vn / 103.176.178.51: 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: ns4.zonedns.vn / 103.28.39.159: 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: ns5.zonedns.vn: 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.
	4. Content- and Performance-critical Checks
	http://duynh.io.vn/.well-known/acme-challenge/check-your-website-dot-server-daten-dot-de 123.21.170.80	-14	Fatal: Check of /.well-known/acme-challenge/random-filename has a timeout. 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.
	http://www.duynh.io.vn/.well-known/acme-challenge/check-your-website-dot-server-daten-dot-de 123.21.170.80	-14	Fatal: Check of /.well-known/acme-challenge/random-filename has a timeout. 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.
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: 441767 milliseconds, 441.767 seconds

8. Connections

No connection informations found. Perhaps only http - connections.

9. Certificates

No certificate informations found. Perhaps only http - connections.

10. Last Certificates - Certificate Transparency Log Check

1. Source CertSpotter - active certificates (one check per day)

No CertSpotter - CT-Log entries found

2. Source crt.sh - old and new certificates, sometimes very slow - only certificates with "not after" > of the last months are listed

No CRT - CT-Log entries found

11. Html-Content - Entries

No Html-Content entries found. Only checked if https + status 200/401/403/404

12. Html-Parsing via https://validator.w3.org/nu/

No https result http status 200 and Content-Type text/html or text/xml found, no Html-Parsing - Check

13. Nameserver - IP-Adresses

Required Root-climbing DNS-Queries to find ip addresses of all Name Servers: ns1.zonedns.vn, ns2.zonedns.vn, ns3.zonedns.vn, ns4.zonedns.vn

QNr.	Domain	Type	NS used
1	vn	NS	f.root-servers.net (2001:500:2f::f)
	Answer: a.dns-servers.vn, b.dns-servers.vn, c.dns-servers.vn, d.dns-servers.vn, e.dns-servers.vn, f.dns-servers.vn, g.dns-servers.vn, h.dns-servers.vn
2	ns1.zonedns.vn	NS	a.dns-servers.vn (2001:678:4::12)
	Answer: ns2001.zonedns.vn, ns2002.zonedns.vn, nsbk.zonedns.vn
	Answer: ns2001.zonedns.vn 103.28.36.27
	Answer: ns2002.zonedns.vn 103.28.36.26
	Answer: nsbk.zonedns.vn 103.176.178.21
3	ns2.zonedns.vn	NS	a.dns-servers.vn (2001:678:4::12)
	Answer: ns2001.zonedns.vn, ns2002.zonedns.vn, nsbk.zonedns.vn
	Answer: ns2001.zonedns.vn 103.28.36.27
	Answer: ns2002.zonedns.vn 103.28.36.26
	Answer: nsbk.zonedns.vn 103.176.178.21
4	ns3.zonedns.vn	NS	a.dns-servers.vn (2001:678:4::12)
	Answer: ns2001.zonedns.vn, ns2002.zonedns.vn, nsbk.zonedns.vn
	Answer: ns2001.zonedns.vn 103.28.36.27
	Answer: ns2002.zonedns.vn 103.28.36.26
	Answer: nsbk.zonedns.vn 103.176.178.21
5	ns4.zonedns.vn	NS	a.dns-servers.vn (2001:678:4::12)
	Answer: ns2001.zonedns.vn, ns2002.zonedns.vn, nsbk.zonedns.vn
	Answer: ns2001.zonedns.vn 103.28.36.27
	Answer: ns2002.zonedns.vn 103.28.36.26
	Answer: nsbk.zonedns.vn 103.176.178.21
6	ns1.zonedns.vn: 64.176.84.220	A	ns2001.zonedns.vn (103.28.36.27)
7	ns1.zonedns.vn: 2401:c080:1400:1cd4:5400:5ff:fe80:ec33	AAAA	ns2001.zonedns.vn (103.28.36.27)
8	ns2.zonedns.vn: 103.176.178.51	A	ns2001.zonedns.vn (103.28.36.27)
9	ns2.zonedns.vn: 2401:c080:1400:1cd4:5400:5ff:fe80:ec33	AAAA	ns2001.zonedns.vn (103.28.36.27)
10	ns3.zonedns.vn: 103.28.36.30	A	ns2001.zonedns.vn (103.28.36.27)
11	ns3.zonedns.vn: 2001:df1:3200::15	AAAA	ns2001.zonedns.vn (103.28.36.27)
12	ns4.zonedns.vn: 103.28.39.159	A	ns2001.zonedns.vn (103.28.36.27)
13	ns4.zonedns.vn: 2001:df1:3200::15	AAAA	ns2001.zonedns.vn (103.28.36.27)

14. CAA - Entries

Domainname	flag	Value	∑ Queries
www.duynh.io.vn			1
duynh.io.vn	0	no CAA entry found	1
io.vn	0	no CAA entry found	1
vn	0	no CAA entry found	1

15. TXT - Entries

Domainname	Status	∑ Queries
duynh.io.vn	ok	1
www.duynh.io.vn		1
_acme-challenge.duynh.io.vn	Name Error - The domain name does not exist	1
_acme-challenge.www.duynh.io.vn	Name Error - The domain name does not exist	1
_acme-challenge.duynh.io.vn.duynh.io.vn	Name Error - The domain name does not exist	1
_acme-challenge.www.duynh.io.vn.duynh.io.vn	Name Error - The domain name does not exist	1
_acme-challenge.www.duynh.io.vn.www.duynh.io.vn	Name Error - The domain name does not exist	1

16. DomainService - Entries

Type		Domain	Pref	Value	num Answers	Status
MX		duynh.io.vn	10	duynh.io.vn	1	ok
	A			123.21.170.80	1	ok
	CNAME				0	ok

17. Cipher Suites

No results

18. Portchecks

No open Ports <> 80 / 443 found, so no additional Ports checked.

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