pro-linux.de

Checked 21 October 2026, 23:51 UTC · via 8.8.8.8
!Passed with warnings
23 passed 2 warnings 0 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

info

dns.pro-linux.de, nsb2.schlundtech.de, nsc2.schlundtech.de, nsd2.schlundtech.de

Found

Parent zone
de
Delegation from
a.nic.de (194.0.0.53)
NS at the parent
dns.pro-linux.de, nsb2.schlundtech.de, nsc2.schlundtech.de, nsd2.schlundtech.de
NS in the zone
dns.pro-linux.de, nsb2.schlundtech.de, nsc2.schlundtech.de, nsd2.schlundtech.de
NameserverAddressesNetwork (AS)Glue
dns.pro-linux.de148.251.87.233 2a01:4f8:202:62e8::2AS24940 HETZNER-AS - Hetzner Online GmbH, DE AS24940 HETZNER-AS - Hetzner Online GmbH, DE148.251.87.233 2a01:4f8:202:62e8::2
nsb2.schlundtech.de185.132.35.227 2607:f1c0:fe:53:185:132:35:227AS15418 IONOS-ANYCAST - Fasthosts Internet Limited, GB AS15418 IONOS-ANYCAST - Fasthosts Internet Limited, GB-
nsc2.schlundtech.de217.160.80.227 2001:8d8:fe:53:217:160:80:227AS8560 IONOS-AS - IONOS SE, DE AS8560 IONOS-AS - IONOS SE, DE-
nsd2.schlundtech.de217.160.81.227 2001:8d8:fe:53:217:160:81:227AS8560 IONOS-AS - IONOS SE, DE AS8560 IONOS-AS - IONOS SE, DE-

Checks

  • ✓ 4 nameservers #6
    Delegated to dns.pro-linux.de, nsb2.schlundtech.de, nsc2.schlundtech.de, nsd2.schlundtech.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.pro-linux.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 4 IPv4 /24s and 3 IPv6 /48s.
  • ✓ 3 autonomous systems #11
    The nameservers are spread over: AS15418 (IONOS-ANYCAST - Fasthosts Internet Limited, GB): 2 addresses; AS24940 (HETZNER-AS - Hetzner Online GmbH, DE): 2 addresses; AS8560 (IONOS-AS - IONOS SE, DE): 4 addresses.
  • 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

warn

8 of 8 addresses answer authoritatively

Found

NameserverAnswerRecursionTCP / EDNSAXFRVersion
dns.pro-linux.de 148.251.87.233NOERROR, 3 ms, authoritativenoyes / yesrefusedNSD 4.6.1
dns.pro-linux.de 2a01:4f8:202:62e8::2NOERROR, 3 ms, authoritativenoyes / yesrefusedNSD 4.6.1
nsb2.schlundtech.de 185.132.35.227NOERROR, 4 ms, authoritativenoyes / yesrefusedServed by PowerDNS - https://www.powerdns.com/
nsb2.schlundtech.de 2607:f1c0:fe:53:185:132:35:227NOERROR, 5 ms, authoritativenoyes / yesrefusedServed by PowerDNS - https://www.powerdns.com/
nsc2.schlundtech.de 217.160.80.227NOERROR, 9 ms, authoritativenoyes / yesrefusedServed by PowerDNS - https://www.powerdns.com/
nsc2.schlundtech.de 2001:8d8:fe:53:217:160:80:227NOERROR, 10 ms, authoritativenoyes / yesrefusedServed by PowerDNS - https://www.powerdns.com/
nsd2.schlundtech.de 217.160.81.227NOERROR, 9 ms, authoritativenoyes / yesrefusedServed by PowerDNS - https://www.powerdns.com/
nsd2.schlundtech.de 2001:8d8:fe:53:217:160:81:227NOERROR, 9 ms, authoritativenoyes / yesrefusedServed by PowerDNS - https://www.powerdns.com/

Checks

  • ✓ All respond #14
    All 8 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: dns.pro-linux.de: "NSD 4.6.1". 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 2026093004 · primary dns.pro-linux.de

Found

Primary (MNAME)
dns.pro-linux.de
Contact (RNAME)
postmaster.www.pro-linux.de
Serial
2026093004
Refresh / retry
86400 s / 1800 s
Expire
2419200 s
Negative TTL
10800 s

Serial per nameserver

NameserverSerial
dns.pro-linux.de (148.251.87.233)2026093004
dns.pro-linux.de (2a01:4f8:202:62e8::2)2026093004
nsb2.schlundtech.de (185.132.35.227)2026093004
nsb2.schlundtech.de (2607:f1c0:fe:53:185:132:35:227)2026093004
nsc2.schlundtech.de (217.160.80.227)2026093004
nsc2.schlundtech.de (2001:8d8:fe:53:217:160:80:227)2026093004
nsd2.schlundtech.de (217.160.81.227)2026093004
nsd2.schlundtech.de (2001:8d8:fe:53:217:160:81:227)2026093004

Checks

  • ✓ Serial 2026093004 everywhere #22
    All nameservers serve the same version of the zone.
  • ✓ Timers within recommendations #23
    SOA refresh 1d, retry 30m, expire 28d, negative TTL 3h.
  • ✓ Primary is a public nameserver #24
    The primary nameserver dns.pro-linux.de is one of the listed nameservers.
  • ✓ Contact postmaster@www.pro-linux.de #25
    The SOA RNAME postmaster.www.pro-linux.de means postmaster@www.pro-linux.de.
  • ✓ Date-based serial #26
    The serial 2026093004 follows the YYYYMMDDnn convention (2026-09-30).

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

9 records at the apex

Found

Read from
148.251.87.233:53
TypeValueTTL
SOAdns.pro-linux.de. postmaster.www.pro-linux.de. 2026093004 86400 1800 2419200 1080086400
NSdns.pro-linux.de.86400
NSnsb2.schlundtech.de.86400
NSnsc2.schlundtech.de.86400
NSnsd2.schlundtech.de.86400
A148.251.87.23386400
AAAA2a01:4f8:202:62e8::286400
MX10 mail.pro-linux.de.86400
TXT"v=spf1 a mx ~all"1800

Checks

  • ✓ TTLs within range #32
    TTLs: A 1d, AAAA 1d, MX 1d, 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