hpi.de

Checked 21 October 2026, 22:50 UTC · via 8.8.8.8
!Passed with warnings
23 passed 1 warning 0 failed 5 info

Registration

info

.de country-code

Found

TLD
.de (country-code)
ICANN policies apply
no

Checks

  • i
    .de is a country-code TLD (ccTLD)
    Country-code TLD: governed by its local registry under national policy, not by an ICANN contract. Registrar accreditation, dispute resolution and RDAP/WHOIS rules are set by the registry.
    #1
  • ✓ TLD delegated and signed #2
    .de is delegated in the root zone and DNSSEC-signed.
  • i
    Registration data not available
    No registration data via RDAP: the registry of .de offers no RDAP service. Many ccTLD registries don't offer RDAP; check the registry's WHOIS instead.
    #3

Delegation

info

dns1.hpi.uni-potsdam.de, mail3.hpi.uni-potsdam.de, www7.hpi.de, www8.hpi-web.de

Found

Parent zone
de
Delegation from
a.nic.de (194.0.0.53)
NS at the parent
dns1.hpi.uni-potsdam.de, mail3.hpi.uni-potsdam.de, www7.hpi.de, www8.hpi-web.de
NS in the zone
dns1.hpi.uni-potsdam.de, mail3.hpi.uni-potsdam.de, www7.hpi.de, www8.hpi-web.de
NameserverAddressesNetwork (AS)Glue
dns1.hpi.uni-potsdam.de141.89.225.97 2001:638:807:204::8d59:e161AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE-
mail3.hpi.uni-potsdam.de141.89.225.123 2001:638:807:204::8d59:e17bAS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE-
www7.hpi.de5.9.159.187AS24940 HETZNER-AS - Hetzner Online GmbH, DE5.9.159.187
www8.hpi-web.de5.9.145.37 2a01:4f8:190:2424::8AS24940 HETZNER-AS - Hetzner Online GmbH, DE AS24940 HETZNER-AS - Hetzner Online GmbH, DE5.9.145.37 2a01:4f8:190:2424::8

Checks

  • ✓ 4 nameservers #6
    Delegated to dns1.hpi.uni-potsdam.de, mail3.hpi.uni-potsdam.de, www7.hpi.de, www8.hpi-web.de.
  • ✓ Parent and zone agree #7
    The parent delegation and the zone's NS records list the same nameservers.
  • ✓ Glue present and correct #8
    Glue is published for the nameservers inside the zone: www7.hpi.de.
  • ✓ All names resolve #9
    Every nameserver name has an address and is not an alias.
  • ✓ Nameservers in different networks #10
    The nameservers are spread over 3 IPv4 /24s and 2 IPv6 /48s.
  • ✓ 2 autonomous systems #11
    The nameservers are spread over: AS24940 (HETZNER-AS - Hetzner Online GmbH, DE): 3 addresses; AS680 (DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE): 4 addresses.
  • i
    All nameserver names under .de
    All nameserver names are under one TLD, so a problem with that TLD also makes the nameservers unreachable. Some operators use names under two TLDs for extra resilience.
    #12
  • i
    Partly IPv6
    These nameservers have no IPv6 address: www7.hpi.de.
    #13

Nameservers

pass

7 of 7 addresses answer authoritatively

Found

NameserverAnswerRecursionTCP / EDNSAXFRVersion
dns1.hpi.uni-potsdam.de 141.89.225.97NOERROR, 15 ms, authoritativenoyes / yesrefused-
dns1.hpi.uni-potsdam.de 2001:638:807:204::8d59:e161NOERROR, 14 ms, authoritativenoyes / yesrefused-
mail3.hpi.uni-potsdam.de 141.89.225.123NOERROR, 15 ms, authoritativenoyes / yesrefused-
mail3.hpi.uni-potsdam.de 2001:638:807:204::8d59:e17bNOERROR, 14 ms, authoritativenoyes / yesrefused-
www7.hpi.de 5.9.159.187NOERROR, 3 ms, authoritativenoyes / yesrefused-
www8.hpi-web.de 5.9.145.37NOERROR, 2 ms, authoritativenoyes / yesrefused-
www8.hpi-web.de 2a01:4f8:190:2424::8NOERROR, 3 ms, authoritativenoyes / yesrefused-

Checks

  • ✓ All respond #14
    All 7 nameserver addresses answered.
  • ✓ All authoritative #15
    Every responding nameserver answers authoritatively for the zone.
  • ✓ No recursion #16
    The nameservers do not answer recursive queries for other domains.
  • ✓ No version disclosed #17
    The nameservers don't reveal their software version.
  • ✓ Zone transfers refused #18
    No nameserver allows a zone transfer to the public.
  • ✓ TCP supported #19
    All nameservers answer over TCP.
  • ✓ EDNS supported #20
    All nameservers support EDNS(0).
  • ✓ Public addresses #21
    All nameserver addresses are publicly routable.

SOA

pass

serial 2026102001 · primary dns1.hpi.uni-potsdam.de

Found

Primary (MNAME)
dns1.hpi.uni-potsdam.de
Contact (RNAME)
admin.hpi.uni-potsdam.de
Serial
2026102001
Refresh / retry
28800 s / 7200 s
Expire
604800 s
Negative TTL
3600 s

Serial per nameserver

NameserverSerial
dns1.hpi.uni-potsdam.de (141.89.225.97)2026102001
dns1.hpi.uni-potsdam.de (2001:638:807:204::8d59:e161)2026102001
mail3.hpi.uni-potsdam.de (141.89.225.123)2026102001
mail3.hpi.uni-potsdam.de (2001:638:807:204::8d59:e17b)2026102001
www7.hpi.de (5.9.159.187)2026102001
www8.hpi-web.de (5.9.145.37)2026102001
www8.hpi-web.de (2a01:4f8:190:2424::8)2026102001

Checks

  • ✓ Serial 2026102001 everywhere #22
    All nameservers serve the same version of the zone.
  • ✓ Timers within recommendations #23
    SOA refresh 8h, retry 2h, expire 7d, negative TTL 1h.
  • ✓ Primary is a public nameserver #24
    The primary nameserver dns1.hpi.uni-potsdam.de is one of the listed nameservers.
  • ✓ Contact admin@hpi.uni-potsdam.de #25
    The SOA RNAME admin.hpi.uni-potsdam.de means admin@hpi.uni-potsdam.de.
  • ✓ Date-based serial #26
    The serial 2026102001 follows the YYYYMMDDnn convention (2026-10-20).

DNSSEC

warn

Not signed

Found

Validated by resolver
no

Checks

  • !
    Not signed
    The zone is not signed with DNSSEC, so answers can be spoofed. Enable DNSSEC at your DNS provider and publish the DS record at your registrar.
    #27

Records

info

28 records at the apex

Found

Read from
141.89.225.97:53
TypeValueTTL
SOAdns1.hpi.uni-potsdam.de. admin.hpi.uni-potsdam.de. 2026102001 28800 7200 604800 36001000
NSmail3.hpi.uni-potsdam.de.1000
NSwww7.hpi.de.1000
NSdns1.hpi.uni-potsdam.de.1000
NSwww8.hpi-web.de.1000
A104.20.37.155300
A172.66.164.76300
AAAA2606:4700:10::ac42:a44c300
AAAA2606:4700:10::6814:259b300
MX20 mail3.hpi.uni-potsdam.de.1000
MX10 mail2.hpi.uni-potsdam.de.1000
TXT"mentimeter-6eeac9ef-e4e9-467c-ab56-e0bc39841ab4"3600
TXT"d365mktkey=gibcDyqoY9eO87F4rw4l9cv8VwirsnRjvRgJcjpDYYgx"3600
TXT"anthropic-domain-verification-15dt6m=23WMzuwhhZHrzEDmsHFYoVdSx"3600
TXT"docusign=d73a39b3-8deb-464f-9ec1-ece9cb3e6121"3600
TXT"miro-verification=d6f0f1c49588e224acbf943e34b7a112f01620e1"3600
TXT"HARICA-eTN75usKDoRotJqF54V"3600
TXT"openai-domain-verification=dv-sEBgIrRGG6Ru1WdPcXAqJLxD"3600
TXT"adobe-idp-site-verification=b6c090cb7d9b25e647241721d58e9c0f409043ed5fee95518cde252f23196f7a"3600
TXT"perplexity-ai-domain-verification-wg1x04=CEGavzabOVuWMBfGqFlXoT1sK"3600
TXT"v=spf1 mx include:_spf.eu.messagegears.net include:spf.protection.outlook.com include:spf.codepiraten.com ip4:141.89.221.252 ip4:141.89.221.132 a:hpi.managed-otrs.com ~all"3600
TXT"successfactors-site-verification=NWM5MGE5OGRiOTlkMzIxNGMzY2MyOTdmNjhlM2IxYzk4MzZjMzFjMzVlYmNhZWJhOGU3ZDMyYTA4NjY1MjliMw=="3600
TXT"apple-domain-verification=yDgbolXT8d89WWs6"3600
TXT"MS=ms44865061"3600
TXT"asv=9daefb29545c062d0113cd9fcb4d5c49"3600
TXT"MS=C81B4AE128C478099F4E9AE8116D784BEBDB871E"3600
TXT"ahrefs-site-verification_035fb4d9bc76499cdbe44d36da7fac1c3c47cc082c72157b3dd0f0202e66b9cf"3600
TXT"google-site-verification=shC4y3WeoKxaiQGgPp51sXkcpV1kn9P451_OrWnxSLc"3600

Checks

  • ✓ TTLs within range #32
    TTLs: A 5m, AAAA 5m, MX 16m40s, NS 16m40s. The NS TTL at the parent is 1d and in the zone 16m40s; resolvers may use either.
  • ✓ No CNAME at the apex #33
    The zone apex has no CNAME record.
  • ✓ No wildcard #34
    Names that don't exist return NXDOMAIN.
  • i
    No CAA records
    Without CAA records any certificate authority may issue certificates for this domain. A CAA record limits issuance to the CAs you use.
    #35