tu-berlin.de

Checked 22 October 2026, 00:41 UTC · via 8.8.8.8
!Passed with warnings
21 passed 2 warnings 0 failed 6 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

dns-2.dfn.de, dns-3.dfn.de, ns.tu-berlin.de

Found

Parent zone
de
Delegation from
a.nic.de (194.0.0.53)
NS at the parent
dns-2.dfn.de, dns-3.dfn.de, ns.tu-berlin.de
NS in the zone
dns-2.dfn.de, dns-3.dfn.de, ns.tu-berlin.de
NameserverAddressesNetwork (AS)Glue
dns-2.dfn.de193.174.75.54 2001:638:d:b102::1AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE-
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-
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

Checks

  • ✓ 3 nameservers #6
    Delegated to dns-2.dfn.de, dns-3.dfn.de, ns.tu-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: ns.tu-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 2 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): 6 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
  • ✓ All reachable over IPv6 #13
    Every nameserver has an IPv6 address.

Nameservers

info

6 of 6 addresses answer authoritatively

Found

NameserverAnswerRecursionTCP / EDNSAXFRVersion
dns-2.dfn.de 193.174.75.54NOERROR, 8 ms, authoritativenoyes / yesrefused0
dns-2.dfn.de 2001:638:d:b102::1NOERROR, 7 ms, authoritativenoyes / yesrefused0
dns-3.dfn.de 193.174.75.58NOERROR, 9 ms, authoritativenoyes / yesrefused0
dns-3.dfn.de 2001:638:d:b103::1NOERROR, 8 ms, authoritativenoyes / yesrefused0
ns.tu-berlin.de 130.149.7.7NOERROR, 14 ms, authoritativenoyes / yesrefused-
ns.tu-berlin.de 2001:638:809:7::7NOERROR, 14 ms, authoritativenoyes / yesrefused-

Checks

  • ✓ All respond #14
    All 6 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-2.dfn.de: "0"; 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 3150920902 · primary ns.tu-berlin.de

Found

Primary (MNAME)
ns.tu-berlin.de
Contact (RNAME)
noc.tubit.tu-berlin.de
Serial
3150920902
Refresh / retry
21600 s / 3600 s
Expire
2592000 s
Negative TTL
900 s

Serial per nameserver

NameserverSerial
dns-2.dfn.de (193.174.75.54)3150920902
dns-2.dfn.de (2001:638:d:b102::1)3150920902
dns-3.dfn.de (193.174.75.58)3150920901
dns-3.dfn.de (2001:638:d:b103::1)3150920901
ns.tu-berlin.de (130.149.7.7)3150920911
ns.tu-berlin.de (2001:638:809:7::7)3150920911

Checks

  • !
    Serials differ
    The nameservers serve different versions of the zone: 3150920901 on dns-3.dfn.de (193.174.75.58), dns-3.dfn.de (2001:638:d:b103::1); 3150920902 on dns-2.dfn.de (193.174.75.54), dns-2.dfn.de (2001:638:d:b102::1); 3150920911 on ns.tu-berlin.de (130.149.7.7), ns.tu-berlin.de (2001:638:809:7::7). 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 1h, expire 30d, negative TTL 15m.
  • ✓ Primary is a public nameserver #24
    The primary nameserver ns.tu-berlin.de is one of the listed nameservers.
  • ✓ Contact noc@tubit.tu-berlin.de #25
    The SOA RNAME noc.tubit.tu-berlin.de means noc@tubit.tu-berlin.de.
  • ✓ Timestamp serial #26
    The serial 3150920902 is a Unix timestamp (2069-11-05 23:48 UTC).

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

20 records at the apex

Found

Read from
193.174.75.54:53
TypeValueTTL
SOAns.tu-berlin.de. noc.tubit.tu-berlin.de. 3150920902 21600 3600 2592000 90028800
NSdns-2.dfn.de.28800
NSns.tu-berlin.de.28800
NSdns-3.dfn.de.28800
A10.150.7.67600
A172.31.25.70600
A10.150.7.70600
A10.150.7.68600
A10.150.7.69600
MX10 b1861.mx.srv.dfn.de.28800
MX10 c1861.mx.srv.dfn.de.28800
MX10 a1861.mx.srv.dfn.de.28800
TXT"ZOOM_verify_IKGVguF2STCWu8Sd23Zv5A"28800
TXT"facebook-domain-verification=uwj0p8p6y8d8nghw46irrznjv5m1sy"28800
TXT"HARICA-BseuKBWWHWXBzDHLFk5"28800
TXT"cisco-ci-domain-verification=5914feda0494aa6850656aa987cbb519e67e24e4adc62372fb11ce5a716fad6f"28800
TXT"HARICA-oLSvVS6GLQKZhFmkyJy"28800
TXT"google-site-verification=kSmcFhy-wb4tugh9q4ixU8FB7Nf_9olms3FAOMvvneA"28800
TXT"google-site-verification=-jwn3NtjIFcWjGY4Iz1yrHpRRKUHnqOKn_uXdSSkFBE"28800
TXT"v=spf1 ip4:130.149.7.33/32 ip4:130.149.7.70/32 ip4:141.23.12.141/32 ip4:141.23.12.142/32 ip4:141.23.12.143/32 ip4:194.95.233.66/32 ip4:194.95.235.66/32 ip4:194.95.239.66/32 ~all"28800

Checks

  • ✓ TTLs within range #32
    TTLs: A 10m, MX 8h, NS 8h. The NS TTL at the parent is 1d and in the zone 8h; 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