SurfaceMap › n › nbn-resolving.de

nbn-resolving.de

Checked 2026-10-21 23:31 UTC · first added 2026-10-21
✗Problems found Score 42 of 100

Domain & DNS

fail

22 passed 3 warn 1 failed

Areas

iRegistration iDelegation ✗Nameservers !SOA !DNSSEC !Records

Problems

  • ✗
    Nameservers not responding
    Nameservers · These addresses did not answer, so resolvers waste time on timeouts: ns0.dnb.de (193.175.100.253): read udp 46.225.38.91:60940->193.175.100.253:53: i/o timeout; ns1.dnb.de (193.175.100.254): read udp 46.225.38.91:59520->193.175.100.254:53: i/o timeout.
    #14
  • !
    Unusual SOA timers
    SOA · retry 1h should be shorter than refresh 1h. Current values: refresh 1h, retry 1h, expire 28d, negative TTL 1h.
    #23
  • !
    NSEC3 with extra iterations or salt
    DNSSEC · NSEC3 uses 100 iterations and a 8-byte salt. RFC 9276 recommends 0 iterations and no salt: extra iterations cost resolvers CPU and add no real protection, and some validators treat high counts as insecure.
    #31
  • !
    Very low TTLs
    Records · These records have a TTL below 5m, causing extra queries and slower lookups: A (1m), MX (1m), NS (1m). Low TTLs are useful just before a planned change. The NS TTL at the parent is 1d and in the zone 1m; resolvers may use either.
    #32

Recent checks

✗

Full report

Domain & DNS report for nbn-resolving.de ›

Mail

fail

9 passed 3 warn 3 failed

Areas

✗SPF ✗DMARC ✗DKIM ✓DNSSEC !MX !TLS iBIMI

Problems

  • ✗
    No DMARC record
    DMARC · No DMARC record was found for this domain. DMARC is essential for preventing email spoofing. Add a DMARC record with p=reject or at least p=quarantine.
    #5
  • ✗
    No SPF record
    SPF · No SPF record was found for this domain. SPF is important for preventing email spoofing. Add an SPF record to specify which servers are authorized to send email for your domain.
    #6
  • ✗
    No DKIM keys published
    DKIM · _domainkey.nbn-resolving.de does not exist (NXDOMAIN), so no DKIM keys are published. DKIM helps prevent email spoofing. Configure DKIM with your email service provider.
    #7
  • !
    Hosts without IPv6
    MX · The following MX hosts could not be resolved to IPv6 addresses: mail.dnb.de
    #11
  • !
    Single MX host, no backup
    MX · Only one MX record found. For better email reliability, consider adding at least one backup MX server.
    #12
  • !
    Not configured
    TLS · MTA-STS is not configured, so other mail servers fall back to unencrypted delivery when TLS fails or is stripped by an attacker. Publish a _mta-sts TXT record and a policy at https://mta-sts.<domain>/.well-known/mta-sts.txt.
    #32

Recent checks

✗

Full report

Mail report for nbn-resolving.de ›