Domain report: fv-bwl.de

Registration

info

.de country-code

Found

TLD: .de (country-code)
ICANN policies apply: no

Checks

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.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.
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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

dns1.belwue.de, dns3.belwue.de, dns5.belwue.de

Found

Parent zone: de
Delegation from: a.nic.de (194.0.0.53)
NS at the parent: dns1.belwue.de, dns3.belwue.de, dns5.belwue.de
NS in the zone: dns1.belwue.de, dns3.belwue.de, dns5.belwue.de

Nameserver	Addresses	Network (AS)	Glue
dns1.belwue.de	129.143.2.10 2001:7c0::53:10	AS553 BELWUE - Universitaet Stuttgart, DE AS553 BELWUE - Universitaet Stuttgart, DE	129.143.2.10 2001:7c0::53:10
dns3.belwue.de	129.143.253.133 2001:7c0:0:253::133	AS553 BELWUE - Universitaet Stuttgart, DE AS553 BELWUE - Universitaet Stuttgart, DE	129.143.253.133 2001:7c0:0:253::133
dns5.belwue.de	129.143.4.5 2001:7c0::53:5	AS553 BELWUE - Universitaet Stuttgart, DE AS553 BELWUE - Universitaet Stuttgart, DE	129.143.4.5 2001:7c0::53:5

Checks

✓ 3 nameservers #6

Delegated to dns1.belwue.de, dns3.belwue.de, dns5.belwue.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.
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One address family in one network

all IPv6 addresses are in 2001:7c0::/48, while the other address family is spread over several networks.

#10
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All nameservers in one AS

All nameserver addresses are announced by one network operator (AS553 (BELWUE - Universitaet Stuttgart, 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
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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

6 of 6 addresses answer authoritatively

Found

Nameserver	Answer	Recursion	TCP / EDNS	AXFR	Version
dns1.belwue.de 129.143.2.10	NOERROR, 7 ms, authoritative	no	yes / yes	refused	PowerDNS Authoritative Server 4.5.5 (built Dec 8 2022 18:24:18 by root@a309361b6303)
dns1.belwue.de 2001:7c0::53:10	NOERROR, 7 ms, authoritative	no	yes / yes	refused	PowerDNS Authoritative Server 4.5.5 (built Dec 8 2022 18:24:18 by root@a309361b6303)
dns3.belwue.de 129.143.253.133	NOERROR, 8 ms, authoritative	no	yes / yes	refused	PowerDNS Authoritative Server 4.5.5 (built Dec 8 2022 18:24:18 by root@a309361b6303)
dns3.belwue.de 2001:7c0:0:253::133	NOERROR, 8 ms, authoritative	no	yes / yes	refused	PowerDNS Authoritative Server 4.5.5 (built Dec 8 2022 18:24:18 by root@a309361b6303)
dns5.belwue.de 129.143.4.5	NOERROR, 7 ms, authoritative	no	yes / yes	refused	PowerDNS Authoritative Server 4.5.5 (built Dec 8 2022 18:24:18 by root@a309361b6303)
dns5.belwue.de 2001:7c0::53:5	NOERROR, 8 ms, authoritative	no	yes / yes	refused	PowerDNS Authoritative Server 4.5.5 (built Dec 8 2022 18:24:18 by root@a309361b6303)

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.
!

Software version disclosed

These nameservers report their software version via version.bind/version.server, which helps attackers find known vulnerabilities: dns1.belwue.de: "PowerDNS Authoritative Server 4.5.5 (built Dec 8 2022 18:24:18 by root@a309361b6303)"; dns3.belwue.de: "PowerDNS Authoritative Server 4.5.5 (built Dec 8 2022 18:24:18 by root@a309361b6303)"; dns5.belwue.de: "PowerDNS Authoritative Server 4.5.5 (built Dec 8 2022 18:24:18 by root@a309361b6303)". 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

warn

serial 2025110601 · primary dns1.bwl.de

Found

Primary (MNAME): dns1.bwl.de
Contact (RNAME): dns.bitbw.bwl.de
Serial: 2025110601
Refresh / retry: 10800 s / 900 s
Expire: 7200 s
Negative TTL: 900 s

Serial per nameserver

Nameserver	Serial
dns1.belwue.de (129.143.2.10)	2025110601
dns1.belwue.de (2001:7c0::53:10)	2025110601
dns3.belwue.de (129.143.253.133)	2025110601
dns3.belwue.de (2001:7c0:0:253::133)	2025110601
dns5.belwue.de (129.143.4.5)	2025110601
dns5.belwue.de (2001:7c0::53:5)	2025110601

Checks

✓ Serial 2025110601 everywhere #22

All nameservers serve the same version of the zone.
!

Unusual SOA timers

expire 2h is shorter than 7d; secondaries stop answering too soon when the primary is down; expire 2h must be longer than refresh + retry. Current values: refresh 3h, retry 15m, expire 2h, negative TTL 15m.

#23
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Hidden master

The primary nameserver dns1.bwl.de is not listed as a nameserver: a hidden master that only feeds the public secondaries. That is a common setup; make sure it is not reachable for zone transfers from outside.

#24
✓ Contact dns@bitbw.bwl.de #25

The SOA RNAME dns.bitbw.bwl.de means dns@bitbw.bwl.de.
✓ Date-based serial #26

The serial 2025110601 follows the YYYYMMDDnn convention (2025-11-06).

DNSSEC

pass

Signed, DS published at parent

Found

Validated by resolver: yes
Denial of existence: NSEC3
NSEC3: 0 iterations, 0-byte salt
Signatures valid until: 29 October 2026

DS at the parent

Key tag	Algorithm	Digest	Matches a key
36094	RSASHA256 (8)	SHA256 0AE9C67F635F40F9…	yes

DNSKEY in the zone

Key tag	Role	Algorithm
36094	KSK (257)	RSASHA256 (8)

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 36094 (SHA256).
✓ Modern algorithms #29

Key algorithms: RSASHA256 (8).
✓ Signatures valid until 2026-10-29 #30

The earliest DNSKEY/SOA signature expires at 2026-10-29 00:00 UTC.
✓ NSEC3 as recommended #31

The zone uses NSEC3 with 0 iterations and no salt (RFC 9276).

Records

info

7 records at the apex

Found

Read from: 129.143.2.10:53

Type	Value	TTL
SOA	dns1.bwl.de. dns.bitbw.bwl.de. 2025110601 10800 900 7200 900	3600
NS	dns5.belwue.de.	3600
NS	dns3.belwue.de.	3600
NS	dns1.belwue.de.	3600
A	195.82.81.36	86400
MX	10 mail1.bwl.de.	86400
TXT	"v=spf1 a mx ip4:195.227.213.228 ip4:195.227.213.229 ip4:195.227.213.231 ip4:195.227.213.232 ip4:193.197.148.18 include:spf.secure-mail.pironet-ndh.com include:spf.nl2go.com -all"	3600

Checks

✓ TTLs within range #32

TTLs: A 1d, MX 1d, 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.
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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