netcologne.de

Checked 21 October 2026, 23:31 UTC · via 8.8.8.8
!Passed with warnings
22 passed 2 warnings 0 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

dns-ext.netcologne.de, dns.techfak.net, ns1.netcologne.de, ns3.netcologne.de, pns.dtag.de

Found

Parent zone
de
Delegation from
a.nic.de (194.0.0.53)
NS at the parent
dns-ext.netcologne.de, dns.techfak.net, ns1.netcologne.de, ns3.netcologne.de, pns.dtag.de
NS in the zone
dns-ext.netcologne.de, dns.techfak.net, ns1.netcologne.de, ns3.netcologne.de, pns.dtag.de
NameserverAddressesNetwork (AS)Glue
dns-ext.netcologne.de134.95.100.209AS5520 UNI-KOELN - Universitaet zu Koeln, DE134.95.100.209
dns.techfak.net129.70.136.153 2001:638:504:2000::f0AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE AS680 DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE-
ns1.netcologne.de194.8.194.70 2001:4dd0:100:1020:53:1:0:1AS8422 NETCOLOGNE - NetCologne Gesellschaft fur Telekommunikation mbH, DE AS8422 NETCOLOGNE - NetCologne Gesellschaft fur Telekommunikation mbH, DE194.8.194.70 2001:4dd0:100:1020:53:1:0:1
ns3.netcologne.de194.8.197.10 2001:4dd0:100:4220:53:1:0:3AS8422 NETCOLOGNE - NetCologne Gesellschaft fur Telekommunikation mbH, DE AS8422 NETCOLOGNE - NetCologne Gesellschaft fur Telekommunikation mbH, DE194.8.197.10 2001:4dd0:100:4220:53:1:0:3
pns.dtag.de194.25.0.125 2003:40:8000::100AS3320 DTAG - Deutsche Telekom AG, DE AS3320 DTAG - Deutsche Telekom AG, DE194.25.0.125 2003:40:8000::100

Checks

  • ✓ 5 nameservers #6
    Delegated to dns-ext.netcologne.de, dns.techfak.net, ns1.netcologne.de, ns3.netcologne.de, pns.dtag.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: dns-ext.netcologne.de, ns1.netcologne.de, ns3.netcologne.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 5 IPv4 /24s and 3 IPv6 /48s.
  • ✓ 4 autonomous systems #11
    The nameservers are spread over: AS3320 (DTAG - Deutsche Telekom AG, DE): 2 addresses; AS5520 (UNI-KOELN - Universitaet zu Koeln, DE): 1 address; AS680 (DFN - Verein zur Foerderung eines Deutschen Forschungsnetzes e.V., DE): 2 addresses; AS8422 (NETCOLOGNE - NetCologne Gesellschaft fur Telekommunikation mbH, DE): 4 addresses.
  • ✓ Nameserver names under 2 TLDs #12
    Nameserver names use the TLDs .de, .net.
  • i
    Partly IPv6
    These nameservers have no IPv6 address: dns-ext.netcologne.de.
    #13

Nameservers

info

9 of 9 addresses answer authoritatively

Found

NameserverAnswerRecursionTCP / EDNSAXFRVersion
dns-ext.netcologne.de 134.95.100.209NOERROR, 11 ms, authoritativenoyes / yesrefused-
dns.techfak.net 129.70.136.153NOERROR, 10 ms, authoritativenoyes / yesrefused-
dns.techfak.net 2001:638:504:2000::f0NOERROR, 10 ms, authoritativenoyes / yesrefused-
ns1.netcologne.de 194.8.194.70NOERROR, 8 ms, authoritativenoyes / yesrefused-
ns1.netcologne.de 2001:4dd0:100:1020:53:1:0:1NOERROR, 8 ms, authoritativenoyes / yesrefused-
ns3.netcologne.de 194.8.197.10NOERROR, 7 ms, authoritativenoyes / yesrefused-
ns3.netcologne.de 2001:4dd0:100:4220:53:1:0:3NOERROR, 7 ms, authoritativenoyes / yesrefused-
pns.dtag.de 194.25.0.125NOERROR, 9 ms, authoritativenoyes / yesrefusedDomainNameServer
pns.dtag.de 2003:40:8000::100NOERROR, 7 ms, authoritativenoyes / yesrefusedDomainNameServer

Checks

  • ✓ All respond #14
    All 9 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: pns.dtag.de: "DomainNameServer".
    #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 2026101901 · primary ns1.netcologne.de

Found

Primary (MNAME)
ns1.netcologne.de
Contact (RNAME)
hostmaster.netcologne.de
Serial
2026101901
Refresh / retry
10800 s / 3600 s
Expire
3024000 s
Negative TTL
1800 s

Serial per nameserver

NameserverSerial
dns-ext.netcologne.de (134.95.100.209)2026101901
dns.techfak.net (129.70.136.153)2026101901
dns.techfak.net (2001:638:504:2000::f0)2026101901
ns1.netcologne.de (194.8.194.70)2026101901
ns1.netcologne.de (2001:4dd0:100:1020:53:1:0:1)2026101901
ns3.netcologne.de (194.8.197.10)2026101901
ns3.netcologne.de (2001:4dd0:100:4220:53:1:0:3)2026101901
pns.dtag.de (194.25.0.125)2026101901
pns.dtag.de (2003:40:8000::100)2026101901

Checks

  • ✓ Serial 2026101901 everywhere #22
    All nameservers serve the same version of the zone.
  • ✓ Timers within recommendations #23
    SOA refresh 3h, retry 1h, expire 35d, negative TTL 30m.
  • ✓ Primary is a public nameserver #24
    The primary nameserver ns1.netcologne.de is one of the listed nameservers.
  • ✓ Contact hostmaster@netcologne.de #25
    The SOA RNAME hostmaster.netcologne.de means hostmaster@netcologne.de.
  • ✓ Date-based serial #26
    The serial 2026101901 follows the YYYYMMDDnn convention (2026-10-19).

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

warn

16 records at the apex

Found

Read from
134.95.100.209:53
TypeValueTTL
SOAns1.netcologne.de. hostmaster.netcologne.de. 2026101901 10800 3600 3024000 18003600
NSns1.netcologne.de.3600
NSdns-ext.netcologne.de.3600
NSdns.techfak.net.3600
NSns3.netcologne.de.3600
NSpns.dtag.de.3600
A213.168.87.2760
AAAA2001:4dd0:100:1f00:80:0:12:560
MX10 cc-mx4.netcologne.de.600
MX10 cc-mx1.netcologne.de.600
MX10 cc-mx2.netcologne.de.600
MX10 cc-mx3.netcologne.de.600
TXT"MS=BDFD7A5ADE83C86F97DF75FD37738FB8BAC068A5"3600
TXT"miro-verification=ad0fc33f95902a578bdf8a8403984837bce5736f"3600
TXT"v=spf1 ip4:89.1.8.0/23 ip6:2001:4dd0:100::/48 ip4:194.8.194.0/24" " ip4:81.173.193.0/24 ip4:81.173.194.0/26 ip4:81.173.246.0/24 ip4:185.98.184.0/24" " ip4:80.82.206.0/26 ip4:46.228.134.9/32 ip4:62.146.4.26/32" " include:spf.pressfile.de ~all"3600
TXT"google-site-verification=5kVCnNbyhYJeE2zfu4UkCKDluoazefAJCpUY357KK2M"3600

Checks

  • !
    Very low TTLs
    These records have a TTL below 5m, causing extra queries and slower lookups: A (1m), AAAA (1m). Low TTLs are useful just before a planned change. The NS TTL at the parent is 1d and in the zone 1h; resolvers may use either.
    #32
  • ✓ 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