mastodon.de

Checked 21 October 2026, 23:21 UTC · via 8.8.8.8
✗Problems found
21 passed 2 warnings 1 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

ns.pfp.de, ns1.mastodon.de

Found

Parent zone
de
Delegation from
a.nic.de (194.0.0.53)
NS at the parent
ns.pfp.de, ns1.mastodon.de
NS in the zone
ns.pfp.de, ns1.mastodon.de
NameserverAddressesNetwork (AS)Glue
ns.pfp.de148.251.94.99 2a01:4f8:202:109a::2AS24940 HETZNER-AS - Hetzner Online GmbH, DE AS24940 HETZNER-AS - Hetzner Online GmbH, DE148.251.94.99 2a01:4f8:202:109a::2
ns1.mastodon.de23.88.43.246 2a01:4f8:c013:4c5b::1AS24940 HETZNER-AS - Hetzner Online GmbH, DE AS24940 HETZNER-AS - Hetzner Online GmbH, DE23.88.43.246 2a01:4f8:c013:4c5b::1

Checks

  • i
    2 nameservers
    Two nameservers meet the minimum; RFC 2182 recommends three or more for important zones: ns.pfp.de, ns1.mastodon.de.
    #6
  • ✓ 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: ns1.mastodon.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 (AS24940 (HETZNER-AS - Hetzner Online GmbH, DE): 4 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

fail

4 of 4 addresses answer authoritatively

Found

NameserverAnswerRecursionTCP / EDNSAXFRVersion
ns.pfp.de 148.251.94.99NOERROR, 3 ms, authoritativenoyes / yesALLOWED (36 records)9.18.43
ns.pfp.de 2a01:4f8:202:109a::2NOERROR, 3 ms, authoritativenoyes / yesALLOWED (36 records)9.18.43
ns1.mastodon.de 23.88.43.246NOERROR, 4 ms, authoritativenoyes / yesrefusedKnot DNS 3.2.6
ns1.mastodon.de 2a01:4f8:c013:4c5b::1NOERROR, 4 ms, authoritativenoyes / yesrefusedKnot DNS 3.2.6

Checks

  • ✓ All respond #14
    All 4 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.pfp.de: "9.18.43"; ns1.mastodon.de: "Knot DNS 3.2.6". Hide or replace the version string.
    #17
  • ✗
    Zone transfer allowed
    These nameservers send the complete zone to anyone who asks (AXFR), exposing all host names: ns.pfp.de (148.251.94.99): 36 records; ns.pfp.de (2a01:4f8:202:109a::2): 36 records. Restrict zone transfers to your secondary servers.
    #18
  • ✓ 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 2025091202 · primary ns1.mastodon.de

Found

Primary (MNAME)
ns1.mastodon.de
Contact (RNAME)
info.mastodon.de
Serial
2025091202
Refresh / retry
3600 s / 1200 s
Expire
604800 s
Negative TTL
600 s

Serial per nameserver

NameserverSerial
ns.pfp.de (148.251.94.99)2025091202
ns.pfp.de (2a01:4f8:202:109a::2)2025091202
ns1.mastodon.de (23.88.43.246)2025091202
ns1.mastodon.de (2a01:4f8:c013:4c5b::1)2025091202

Checks

  • ✓ Serial 2025091202 everywhere #22
    All nameservers serve the same version of the zone.
  • ✓ Timers within recommendations #23
    SOA refresh 1h, retry 20m, expire 7d, negative TTL 10m.
  • ✓ Primary is a public nameserver #24
    The primary nameserver ns1.mastodon.de is one of the listed nameservers.
  • ✓ Contact info@mastodon.de #25
    The SOA RNAME info.mastodon.de means info@mastodon.de.
  • ✓ Date-based serial #26
    The serial 2025091202 follows the YYYYMMDDnn convention (2025-09-12).

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

13 records at the apex

Found

Read from
148.251.94.99:53
TypeValueTTL
SOAns1.mastodon.de. info.mastodon.de. 2025091202 3600 1200 604800 6003600
NSns1.mastodon.de.3600
NSns.pfp.de.3600
A5.9.120.743600
AAAA2a01:4f8:162:706f::23600
MX2 mx01.ionos.de.3600
MX1 mx00.ionos.de.3600
TXT"google-site-verification=AOK39u64SCshlx2TXskr3CmIdNFZHVIJsdI_Q2F2_vk"3600
TXT"v=spf1 include:_spf-eu.ionos.com ~all"3600
CAA0 issue "digicert.com"3600
CAA0 issue "letsencrypt.org"3600
CAA0 issue "pki.goog"3600
CAA0 iodef "mailto:info@mastodon.de"3600

Checks

  • ✓ TTLs within range #32
    TTLs: A 1h, AAAA 1h, MX 1h, NS 1h. The NS TTL at the parent is 1d and in the zone 1h; 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.
  • ✓ CAA restricts issuance #35
    Certificates may be issued by: digicert.com, letsencrypt.org, pki.goog.