mpi-bremen.de

Checked 21 October 2026, 23:30 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-1.dfn.de, dns-2.dfn.de, ns-ext.mpi-bremen.de

Found

Parent zone
de
Delegation from
a.nic.de (194.0.0.53)
NS at the parent
dns-1.dfn.de, dns-2.dfn.de, ns-ext.mpi-bremen.de
NS in the zone
dns-1.dfn.de, dns-2.dfn.de, ns-ext.mpi-bremen.de
NameserverAddressesNetwork (AS)Glue
dns-1.dfn.de193.174.75.50 2001:638:d:b101::1AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE-
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-
ns-ext.mpi-bremen.de194.95.6.36AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE194.95.6.36

Checks

  • ✓ 3 nameservers #6
    Delegated to dns-1.dfn.de, dns-2.dfn.de, ns-ext.mpi-bremen.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-ext.mpi-bremen.de.
  • ✓ All names resolve #9
    Every nameserver name has an address and is not an alias.
  • i
    One address family in one network
    all IPv6 addresses are in 2001:638:d::/48, while the other address family is spread over several networks.
    #10
  • 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): 5 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: ns-ext.mpi-bremen.de.
    #13

Nameservers

warn

5 of 5 addresses answer authoritatively

Found

NameserverAnswerRecursionTCP / EDNSAXFRVersion
dns-1.dfn.de 193.174.75.50NOERROR, 12 ms, authoritativenoyes / yesrefused0
dns-1.dfn.de 2001:638:d:b101::1NOERROR, 14 ms, authoritativenoyes / yesrefused0
dns-2.dfn.de 193.174.75.54NOERROR, 7 ms, authoritativenoyes / yesrefused0
dns-2.dfn.de 2001:638:d:b102::1NOERROR, 7 ms, authoritativenoyes / yesrefused0
ns-ext.mpi-bremen.de 194.95.6.36NOERROR, 12 ms, authoritativenoyes / yesrefused9.18.49-1~deb12u2-Debian

Checks

  • ✓ All respond #14
    All 5 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.
  • !
    Software version disclosed
    These nameservers report their software version via version.bind/version.server, which helps attackers find known vulnerabilities: ns-ext.mpi-bremen.de: "9.18.49-1~deb12u2-Debian". Hide or replace the version string.
    #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

pass

serial 2026081302 · primary ns-ext.mpi-bremen.de

Found

Primary (MNAME)
ns-ext.mpi-bremen.de
Contact (RNAME)
hostmaster.mpi-bremen.de
Serial
2026081302
Refresh / retry
36000 s / 3600 s
Expire
3600000 s
Negative TTL
86400 s

Serial per nameserver

NameserverSerial
dns-1.dfn.de (193.174.75.50)2026081302
dns-1.dfn.de (2001:638:d:b101::1)2026081302
dns-2.dfn.de (193.174.75.54)2026081302
dns-2.dfn.de (2001:638:d:b102::1)2026081302
ns-ext.mpi-bremen.de (194.95.6.36)2026081302

Checks

  • ✓ Serial 2026081302 everywhere #22
    All nameservers serve the same version of the zone.
  • ✓ Timers within recommendations #23
    SOA refresh 10h, retry 1h, expire 1000h, negative TTL 1d.
  • ✓ Primary is a public nameserver #24
    The primary nameserver ns-ext.mpi-bremen.de is one of the listed nameservers.
  • ✓ Contact hostmaster@mpi-bremen.de #25
    The SOA RNAME hostmaster.mpi-bremen.de means hostmaster@mpi-bremen.de.
  • ✓ Date-based serial #26
    The serial 2026081302 follows the YYYYMMDDnn convention (2026-08-13).

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

pass

16 records at the apex

Found

Read from
193.174.75.50:53
TypeValueTTL
SOAns-ext.mpi-bremen.de. hostmaster.mpi-bremen.de. 2026081302 36000 3600 3600000 8640086400
NSns-ext.mpi-bremen.de.86400
NSdns-1.dfn.de.86400
NSdns-2.dfn.de.86400
A194.95.6.40600
MX10 edge-01.mpi-bremen.de.300
TXT"apple-domain-verification=cBIEfKf3onVUEHJO"3600
TXT"adobe-idp-site-verification=c0011d03d13b7c0374b2b3bc3499c8fab8e057db7aff622b8f23cda3ec16b20a"3600
TXT"hibp-verify=dweb_gaadulcuo7t1xpoa15l4leyt"3600
TXT"zdiscover https://mail.mpi-bremen.de/webapp/"3600
TXT"MS=ms38487352"3600
TXT"v=spf1 ip4:194.95.6.0/23 ip4:134.102.40.0/28 a mx include:spf.gwdg.de -all"3600
TXT"cisco-ci-domain-verification=6bfd2f2627bc8461dfb7a6da11b0f7ef08f4bdf2aa661670dcdbcf3b089f2559"3600
CAA0 issuemail "harica.gr"86400
CAA0 issue "harica.gr"86400
CAA0 issuewild "harica.gr"86400

Checks

  • ✓ TTLs within range #32
    TTLs: A 10m, MX 5m, NS 1d.
  • ✓ No CNAME at the apex #33
    The zone apex has no CNAME record.
  • ✓ No wildcard #34
    Names that don't exist return NXDOMAIN.
  • ✓ CAA restricts issuance #35
    Certificates may be issued by: harica.gr.