arcor.de

Checked 21 October 2026, 21:30 UTC · via 8.8.8.8
iAll checks passed
26 passed 0 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

ns1.arcor-ip.de, ns2.arcor-ip.de, ns3.arcor-ip.de

Found

Parent zone
de
Delegation from
a.nic.de (194.0.0.53)
NS at the parent
ns1.arcor-ip.de, ns2.arcor-ip.de, ns3.arcor-ip.de
NS in the zone
ns1.arcor-ip.de, ns2.arcor-ip.de, ns3.arcor-ip.de
NameserverAddressesNetwork (AS)Glue
ns1.arcor-ip.de145.253.2.144 2a01:860:0:202::53AS3209 VODANET - Vodafone GmbH, DE AS3209 VODANET - Vodafone GmbH, DE145.253.2.144 2a01:860:0:202::53
ns2.arcor-ip.de145.253.3.16 2a01:860:0:203::53AS3209 VODANET - Vodafone GmbH, DE AS3209 VODANET - Vodafone GmbH, DE145.253.3.16 2a01:860:0:203::53
ns3.arcor-ip.de145.253.3.20 2a01:860:0:204::53AS3209 VODANET - Vodafone GmbH, DE AS3209 VODANET - Vodafone GmbH, DE145.253.3.20 2a01:860:0:204::53

Checks

  • ✓ 3 nameservers #6
    Delegated to ns1.arcor-ip.de, ns2.arcor-ip.de, ns3.arcor-ip.de.
  • ✓ Parent and zone agree #7
    The parent delegation and the zone's NS records list the same nameservers.
  • ✓ No glue needed #8
    All nameservers are outside the zone, so no glue records are needed.
  • ✓ 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 2a01:860::/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 (AS3209 (VODANET - Vodafone GmbH, 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

pass

6 of 6 addresses answer authoritatively

Found

NameserverAnswerRecursionTCP / EDNSAXFRVersion
ns1.arcor-ip.de 145.253.2.144NOERROR, 4 ms, authoritativenoyes / yesrefused-
ns1.arcor-ip.de 2a01:860:0:202::53NOERROR, 4 ms, authoritativenoyes / yesrefused-
ns2.arcor-ip.de 145.253.3.16NOERROR, 12 ms, authoritativenoyes / yesrefused-
ns2.arcor-ip.de 2a01:860:0:203::53NOERROR, 14 ms, authoritativenoyes / yesrefused-
ns3.arcor-ip.de 145.253.3.20NOERROR, 9 ms, authoritativenoyes / yesrefused-
ns3.arcor-ip.de 2a01:860:0:204::53NOERROR, 9 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.
  • ✓ 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 2025063414 · primary ns1.arcor-ip.de

Found

Primary (MNAME)
ns1.arcor-ip.de
Contact (RNAME)
hostmaster.adm.arcor.net
Serial
2025063414
Refresh / retry
28800 s / 14400 s
Expire
1814400 s
Negative TTL
7200 s

Serial per nameserver

NameserverSerial
ns1.arcor-ip.de (145.253.2.144)2025063414
ns1.arcor-ip.de (2a01:860:0:202::53)2025063414
ns2.arcor-ip.de (145.253.3.16)2025063414
ns2.arcor-ip.de (2a01:860:0:203::53)2025063414
ns3.arcor-ip.de (145.253.3.20)2025063414
ns3.arcor-ip.de (2a01:860:0:204::53)2025063414

Checks

  • ✓ Serial 2025063414 everywhere #22
    All nameservers serve the same version of the zone.
  • ✓ Timers within recommendations #23
    SOA refresh 8h, retry 4h, expire 21d, negative TTL 2h.
  • ✓ Primary is a public nameserver #24
    The primary nameserver ns1.arcor-ip.de is one of the listed nameservers.
  • ✓ Contact hostmaster@adm.arcor.net #25
    The SOA RNAME hostmaster.adm.arcor.net means hostmaster@adm.arcor.net.
  • ✓ Timestamp serial #26
    The serial 2025063414 is a Unix timestamp (2034-03-04 05:36 UTC).

DNSSEC

info

Signed, DS published at parent

Found

Validated by resolver
yes
Denial of existence
NSEC
Signatures valid until
13 November 2026

DS at the parent

Key tagAlgorithmDigestMatches a key
51267ECDSAP256SHA256 (13)SHA256 083298D14F493632…yes

DNSKEY in the zone

Key tagRoleAlgorithm
51267KSK (257)ECDSAP256SHA256 (13)
35483ZSK (256)ECDSAP256SHA256 (13)

Checks

  • ✓ Signed and validated #27
    The zone is signed, the parent publishes a DS record, and the resolver validates the answers.
  • ✓ DS matches a key #28
    The DS record at the parent matches a key in the zone: key tag 51267 (SHA256).
  • ✓ Modern algorithms #29
    Key algorithms: ECDSAP256SHA256 (13).
  • ✓ Signatures valid until 2026-11-13 #30
    The earliest DNSKEY/SOA signature expires at 2026-11-13 00:12 UTC.
  • i
    NSEC
    The zone uses NSEC, so its full contents can be listed by walking the NSEC chain. That is fine unless the names are sensitive.
    #31

Records

info

12 records at the apex

Found

Read from
145.253.2.144:53
TypeValueTTL
SOAns1.arcor-ip.de. hostmaster.adm.arcor.net. 2025063414 28800 14400 1814400 72007200
NSns1.arcor-ip.de.7200
NSns2.arcor-ip.de.7200
NSns3.arcor-ip.de.7200
A45.60.74.50600
MX10 mx3.vodafonemail.de.300
MX10 mx5.vodafonemail.de.300
TXT"google-site-verification=NT2vvu_tWKinC6eWjpuzXqqc07aQFLY4Tehzdm4E20k"3600
TXT"hwtxnzty12b972s10q0t5hmbwzr6ncnv"3600
TXT"v=spf1 include:vodafonemail.de ~all"3600
TXT"_i84b63jnlge01mfsfbpy2qoml8hjq8u"3600
TXT"a24fb2109d294160b507988f88a12fa0"3600

Checks

  • ✓ TTLs within range #32
    TTLs: A 10m, MX 5m, NS 2h. The NS TTL at the parent is 1d and in the zone 2h; 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