hu-berlin.de

Checked 21 October 2026, 22:51 UTC · via 8.8.8.8
!Passed with warnings
20 passed 2 warnings 0 failed 7 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

buffy.cms.hu-berlin.de, dns-3.dfn.de, hpcom.rz.hu-berlin.de, ns.tu-berlin.de, suncom.rz.hu-berlin.de

Found

Parent zone
de
Delegation from
a.nic.de (194.0.0.53)
NS at the parent
buffy.cms.hu-berlin.de, dns-3.dfn.de, hpcom.rz.hu-berlin.de, ns.tu-berlin.de, suncom.rz.hu-berlin.de
NS in the zone
buffy.cms.hu-berlin.de, dns-3.dfn.de, hpcom.rz.hu-berlin.de, ns.tu-berlin.de, suncom.rz.hu-berlin.de
NameserverAddressesNetwork (AS)Glue
buffy.cms.hu-berlin.de141.20.2.3AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE141.20.2.3
dns-3.dfn.de193.174.75.58 2001:638:d:b103::1AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE-
hpcom.rz.hu-berlin.de141.20.1.3AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE141.20.1.3
ns.tu-berlin.de130.149.7.7 2001:638:809:7::7AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE130.149.7.7 2001:638:809:7::7
suncom.rz.hu-berlin.de141.20.1.31AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE141.20.1.31

Checks

  • ✓ 5 nameservers #6
    Delegated to buffy.cms.hu-berlin.de, dns-3.dfn.de, hpcom.rz.hu-berlin.de, ns.tu-berlin.de, suncom.rz.hu-berlin.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: buffy.cms.hu-berlin.de, hpcom.rz.hu-berlin.de, suncom.rz.hu-berlin.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 4 IPv4 /24s and 2 IPv6 /48s.
  • i
    All nameservers in one AS
    All nameserver addresses are announced by one network operator (AS680 (DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE): 7 addresses). An outage or attack on that network affects all nameservers; large anycast providers mitigate this, but a secondary DNS provider adds independence.
    #11
  • 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: buffy.cms.hu-berlin.de, hpcom.rz.hu-berlin.de, suncom.rz.hu-berlin.de.
    #13

Nameservers

info

7 of 7 addresses answer authoritatively

Found

NameserverAnswerRecursionTCP / EDNSAXFRVersion
buffy.cms.hu-berlin.de 141.20.2.3NOERROR, 13 ms, authoritativenoyes / yesrefused-
dns-3.dfn.de 193.174.75.58NOERROR, 10 ms, authoritativenoyes / yesrefused0
dns-3.dfn.de 2001:638:d:b103::1NOERROR, 10 ms, authoritativenoyes / yesrefused0
hpcom.rz.hu-berlin.de 141.20.1.3NOERROR, 13 ms, authoritativenoyes / yesrefused-
ns.tu-berlin.de 130.149.7.7NOERROR, 13 ms, authoritativenoyes / yesrefused-
ns.tu-berlin.de 2001:638:809:7::7NOERROR, 14 ms, authoritativenoyes / yesrefused-
suncom.rz.hu-berlin.de 141.20.1.31NOERROR, 13 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.
  • i
    Identifying string disclosed
    These nameservers answer version queries with a string that is not a version number: dns-3.dfn.de: "0".
    #17
  • ✓ 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

warn

serial 2019101612 · primary hpcom.rz.hu-berlin.de

Found

Primary (MNAME)
hpcom.rz.hu-berlin.de
Contact (RNAME)
dstoye.cms.hu-berlin.de
Serial
2019101612
Refresh / retry
21600 s / 1800 s
Expire
604800 s
Negative TTL
300 s

Serial per nameserver

NameserverSerial
buffy.cms.hu-berlin.de (141.20.2.3)2019101612
dns-3.dfn.de (193.174.75.58)2019101598
dns-3.dfn.de (2001:638:d:b103::1)2019101598
hpcom.rz.hu-berlin.de (141.20.1.3)2019101612
ns.tu-berlin.de (130.149.7.7)2019101601
ns.tu-berlin.de (2001:638:809:7::7)2019101601
suncom.rz.hu-berlin.de (141.20.1.31)2019101612

Checks

  • !
    Serials differ
    The nameservers serve different versions of the zone: 2019101598 on dns-3.dfn.de (193.174.75.58), dns-3.dfn.de (2001:638:d:b103::1); 2019101601 on ns.tu-berlin.de (130.149.7.7), ns.tu-berlin.de (2001:638:809:7::7); 2019101612 on buffy.cms.hu-berlin.de (141.20.2.3), hpcom.rz.hu-berlin.de (141.20.1.3), suncom.rz.hu-berlin.de (141.20.1.31). This is normal for a few minutes after a change; if it lasts, zone transfers to the secondaries are failing.
    #22
  • ✓ Timers within recommendations #23
    SOA refresh 6h, retry 30m, expire 7d, negative TTL 5m.
  • ✓ Primary is a public nameserver #24
    The primary nameserver hpcom.rz.hu-berlin.de is one of the listed nameservers.
  • ✓ Contact dstoye@cms.hu-berlin.de #25
    The SOA RNAME dstoye.cms.hu-berlin.de means dstoye@cms.hu-berlin.de.
  • ✓ Date-based serial #26
    The serial 2019101612 follows the YYYYMMDDnn convention (2019-10-16).

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

15 records at the apex

Found

Read from
141.20.2.3:53
TypeValueTTL
SOAhpcom.rz.hu-berlin.de. dstoye.cms.hu-berlin.de. 2019101612 21600 1800 604800 300172800
NShpcom.rz.hu-berlin.de.172800
NSbuffy.cms.hu-berlin.de.172800
NSdns-3.dfn.de.172800
NSns.tu-berlin.de.172800
NSsuncom.rz.hu-berlin.de.172800
A141.20.4.1803600
MX100 ir2.cms.hu-berlin.de.3600
MX100 ir1.cms.hu-berlin.de.3600
TXT"HARICA-uJcB3Qsl5sonT8rQKtR"3600
TXT"v=spf1 redirect=_spf.hu-berlin.de"3600
TXT"HARICA-D11HHWDWARmhgYlTsSt"3600
TXT"HARICA-U9FCfuSvjSP90Fbb3nO"3600
TXT"adobe-idp-site-verification=50fe2a3f158cf92d09462c79d21f399af9e33adcc0f9eb1f855a39d4408aa72a"3600
TXT"HARICA-LxmP07no7bekBWahpMv"3600

Checks

  • ✓ TTLs within range #32
    TTLs: A 1h, MX 1h, NS 2d. The NS TTL at the parent is 1d and in the zone 2d; 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