hwk-koeln.de

Checked 21 October 2026, 22:51 UTC · via 8.8.8.8
✗Problems found
18 passed 3 warnings 4 failed 4 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

warn

einstein.tillnet.de, ns2.dnsresolve.net

Found

Parent zone
de
Delegation from
a.nic.de (194.0.0.53)
NS at the parent
einstein.tillnet.de, ns2.dnsresolve.net
NS in the zone
einstein.tillnet.de, ns2.dnsresolve.net
NameserverAddressesNetwork (AS)Glue
einstein.tillnet.de89.58.26.16AS197540 netcup-AS - netcup GmbH, DE89.58.26.16
ns2.dnsresolve.net193.254.185.231AS25504 CRONON-AS - Vautron Rechenzentrum AG, DE-

Checks

  • i
    2 nameservers
    Two nameservers meet the minimum; RFC 2182 recommends three or more for important zones: einstein.tillnet.de, ns2.dnsresolve.net.
    #6
  • ✓ 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.
  • ✓ Nameservers in different networks #10
    The nameservers are spread over 2 IPv4 /24s and 0 IPv6 /48s.
  • ✓ 2 autonomous systems #11
    The nameservers are spread over: AS197540 (netcup-AS - netcup GmbH, DE): 1 address; AS25504 (CRONON-AS - Vautron Rechenzentrum AG, DE): 1 address.
  • ✓ Nameserver names under 2 TLDs #12
    Nameserver names use the TLDs .de, .net.
  • !
    No IPv6
    None of the nameservers has an IPv6 address, so IPv6-only resolvers can't reach them.
    #13

Nameservers

fail

1 of 2 addresses answer authoritatively

Found

NameserverAnswerRecursionTCP / EDNSAXFRVersion
einstein.tillnet.de 89.58.26.16NOERROR, 0 ms, authoritativeOPENyes / yesALLOWED (114 records)9.16.22-Debian
ns2.dnsresolve.net 193.254.185.231SERVFAIL, 13 ms, NOT authoritativenono / yesrefused9.16.27-Debian

Checks

  • ✓ All respond #14
    All 2 nameserver addresses answered.
  • ✗
    Lame delegation
    These nameservers don't answer authoritatively for the zone, so resolvers ignore them: ns2.dnsresolve.net (193.254.185.231): SERVFAIL, authoritative=false.
    #15
  • ✗
    Open recursion
    These nameservers resolve names for anyone, which makes them usable for DNS amplification attacks and cache poisoning: einstein.tillnet.de (89.58.26.16). Disable recursion on authoritative servers.
    #16
  • !
    Software version disclosed
    These nameservers report their software version via version.bind/version.server, which helps attackers find known vulnerabilities: einstein.tillnet.de: "9.16.22-Debian"; ns2.dnsresolve.net: "9.16.27-Debian". 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: einstein.tillnet.de (89.58.26.16): 114 records. Restrict zone transfers to your secondary servers.
    #18
  • ✗
    No DNS over TCP
    DNS over TCP is required (RFC 7766); without it, large answers such as DNSSEC responses fail. Not answering over TCP: ns2.dnsresolve.net (193.254.185.231): .
    #19
  • ✓ EDNS supported #20
    All nameservers support EDNS(0).
  • ✓ Public addresses #21
    All nameserver addresses are publicly routable.

SOA

pass

serial 2026072904 · primary einstein.tillnet.de

Found

Primary (MNAME)
einstein.tillnet.de
Contact (RNAME)
root.einstein.tillnet.de
Serial
2026072904
Refresh / retry
28800 s / 7200 s
Expire
604800 s
Negative TTL
86400 s

Checks

  • ✓ Serial 2026072904 everywhere #22
    All nameservers serve the same version of the zone.
  • ✓ Timers within recommendations #23
    SOA refresh 8h, retry 2h, expire 7d, negative TTL 1d.
  • ✓ Primary is a public nameserver #24
    The primary nameserver einstein.tillnet.de is one of the listed nameservers.
  • ✓ Contact root@einstein.tillnet.de #25
    The SOA RNAME root.einstein.tillnet.de means root@einstein.tillnet.de.
  • ✓ Date-based serial #26
    The serial 2026072904 follows the YYYYMMDDnn convention (2026-07-29).

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

17 records at the apex

Found

Read from
89.58.26.16:53
TypeValueTTL
SOAeinstein.tillnet.de. root.einstein.tillnet.de. 2026072904 28800 7200 604800 8640086400
NSns2.dnsresolve.net.86400
NSeinstein.tillnet.de.86400
A176.95.69.164300
MX10 hwkkoeln-de0i.mail.protection.outlook.com.3600
TXT"Foxit-domain-verification=f09f2d301e72eafe220b6c244f7e8eb5"3600
TXT"apple-domain-verification=WgLdqNPYCG8DCddE"3600
TXT"adobe-idp-site-verification=1fa2d1ddc726e0eb932946553b6f54fee86831f27d2f07629987a4dde4532384"3600
TXT"google-site-verification=GlLgmk5GOa6KLpZnqhx1bzWBgbqG02l-Xm5nmjBZy9Y"3600
TXT"google-site-verification=_t8L_Ez8TaAiiEetZiIhOv0cgaeQB7lyNWtL0-kgCtI"3600
TXT"apple-domain-verification=eNVUO3aR4QrpNWQR"3600
TXT"ZOOM_verify_j5qNmCppQjG-UypMA6S8ZA"3600
TXT"ms-domain-verification=139ee561-a416-40b9-a4c0-829fb4873ed9"3600
TXT"MS=ms71810921"3600
TXT"facebook-domain-verification=440x6g0u2d5jc8dxsj9jgx746v50gs"3600
TXT"7tSKd9wi7lz80f266Ya8W6cuzdwuuFzuQCTG/m7S1yS9T56xQ2PpgzQphWBa1Ap23j6Ifrgc3pKUUw23z3gNfQ=="3600
TXT"v=spf1 ip4:212.184.181.170 ip4:212.184.181.171 ip4:195.145.108.151 ip4:195.145.108.152 ip4:176.95.69.188 include:spf.protection.outlook.com include:spf-de.emailsignatures365.com -all"3600

Checks

  • ✓ TTLs within range #32
    TTLs: A 5m, MX 1h, 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.
  • 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