Engineer's DNS Intelligence Report
This domain uses short TTLs across 3 record types (A record at 30s), consistent with DNS-based traffic management (GSLB). Enterprises operating large anycast networks intentionally use short TTLs to enable rapid failover, geographic steering, and load distribution. This is a deliberate infrastructure choice, not a misconfiguration. RFC 1035 §3.2.1 permits any TTL value the zone administrator selects. The findings below reflect deviation from typical values for reference, not necessarily actionable recommendations for this class of infrastructure.
The following DNS record TTLs deviate from typical values. For domains using DNS-based traffic management, short TTLs are expected and intentional.
| Record Type | Observed TTL | Typical TTL | Severity | Context |
|---|---|---|---|---|
| A | 30s |
1 hour (3600s) |
high | A TTL is below typical — observed 30s, typical value is 1 hour (3600s). Short TTLs increase DNS query volume but enable faster propagation. If you are preparing for a migration or need rapid failover, this may be intentional (RFC 1035 §3.2.1). For steady-state production, consider 3600 seconds per NIST SP 800-53 SI-18 relevance guidance. Use the TTL Tuner for profile-specific recommendations. |
| TXT | 4 minutes (240s) |
1 hour (3600s) |
high | TXT TTL is below typical — observed 4 minutes (240s), typical value is 1 hour (3600s). Short TTLs increase DNS query volume but enable faster propagation. If you are preparing for a migration or need rapid failover, this may be intentional (RFC 1035 §3.2.1). For steady-state production, consider 3600 seconds per NIST SP 800-53 SI-18 relevance guidance. Use the TTL Tuner for profile-specific recommendations. |
| NS | 359 minutes (21540s) |
1 day (86400s) |
medium | NS TTL is below typical — observed 359 minutes (21540s), typical value is 1 day (86400s). Short TTLs increase DNS query volume but enable faster propagation. If you are preparing for a migration or need rapid failover, this may be intentional (RFC 1035 §3.2.1). For steady-state production, consider 86400 seconds per NIST SP 800-53 SI-18 relevance guidance. Use the TTL Tuner for profile-specific recommendations. |
| MX | 5 minutes (300s) |
1 hour (3600s) |
high | MX TTL is below typical — observed 5 minutes (300s), typical value is 1 hour (3600s). Short TTLs increase DNS query volume but enable faster propagation. If you are preparing for a migration or need rapid failover, this may be intentional (RFC 1035 §3.2.1). For steady-state production, consider 3600 seconds per NIST SP 800-53 SI-18 relevance guidance. Use the TTL Tuner for profile-specific recommendations. |
| AAAA | 30s |
1 hour (3600s) |
high | AAAA TTL is below typical — observed 30s, typical value is 1 hour (3600s). Short TTLs increase DNS query volume but enable faster propagation. If you are preparing for a migration or need rapid failover, this may be intentional (RFC 1035 §3.2.1). For steady-state production, consider 3600 seconds per NIST SP 800-53 SI-18 relevance guidance. Use the TTL Tuner for profile-specific recommendations. |
Big Picture Questions
- This domain runs short TTLs across multiple record types. Does it operate a global anycast network where DNS-based traffic steering justifies the query volume?
- Are the short TTLs enabling active failover, geographic routing, or load distribution — or are they leftover from a migration that was never reverted?
- Enterprise-grade DNS infrastructure (sub-5ms authoritative response times, globally distributed nameservers) absorbs short-TTL query volume. Would your authoritative DNS handle the same load?
bayan.ns.cloudflare.com
2397853741
dns.cloudflare.com
| Timer | Value | RFC 1912 Range |
|---|---|---|
| Refresh | 10000s | 1,200–43,200s (20 min – 12 hrs) |
| Retry | 2400s | Fraction of Refresh |
| Expire | 604800s | 1,209,600–2,419,200s (14–28 days) |
| Minimum (Neg. Cache) | 1800s | 300–86,400s (5 min – 1 day) |
Independent RFC compliance assessment for Cloudflare. Each finding cites the specific RFC section and reports what the engineering community consensus is. We report honestly — if a provider deviates from standards, we explain what they did differently and what the RFCs actually say.
Cloudflare sets SOA Expire to 604,800 seconds (7 days). RFC 1912 §2.2 recommends 1,209,600–2,419,200 seconds (14–28 days). This means secondary nameservers stop serving the zone sooner if the primary becomes unreachable. Cloudflare's position is that their anycast architecture makes traditional zone transfer semantics less relevant. SOA timers are not editable on Free, Pro, or Business plans.
Cloudflare overrides the zone administrator's TTL to 300 seconds for all proxied (orange-cloud) records. RFC 2181 §5.2 requires TTL uniformity within an RRset but does not mandate a specific value. As the authoritative server, Cloudflare is technically within its rights, but the administrator loses TTL control. This can affect ACME DNS-01 challenges and automation workflows that depend on rapid propagation.
RFC 1912 recommends YYYYMMDDNN format for SOA serial numbers (e.g., 2026022501). Cloudflare uses a proprietary serial number format that does not encode the date. RFC 1035 only requires the serial to increment on changes, so this is compliant with the mandatory standard but breaks the convention relied on by monitoring tools.
Cloudflare's SOA MINIMUM (negative cache TTL) is 1,800–3,600 seconds (30–60 minutes). This controls how long resolvers cache NXDOMAIN responses. Newly created DNS records — including ACME DNS-01 challenge TXT records for Let's Encrypt — may be invisible for up to 1 hour even after creation. This causes certificate issuance failures for automation tools like cert-manager and Traefik. Workaround: pre-create placeholder records before they're needed. This is RFC-compliant but aggressive compared to the 300–900 seconds common at other providers.
In February 2022, Cloudflare's resolver (1.1.1.1) returned CNAME responses with mismatched TTLs within the same RRset — including cases where one TTL was zero and another was non-zero. RFC 2181 §5.2 explicitly states: 'the TTLs of all RRs in an RRSet must be the same.' systemd-resolved (used by Arch Linux, Ubuntu, Fedora, and most modern Linux distributions) correctly rejected these responses per the RFC, causing widespread DNS resolution failures. Cloudflare acknowledged the issue and it appears to have been fixed, but it demonstrated that Cloudflare's DNS infrastructure can deviate from RFC requirements in ways that break compliant resolver implementations.
Your DMARC policy is set to quarantine. Upgrade to p=reject for maximum protection — reject instructs receivers to discard spoofed mail entirely rather than quarantining it.
| Field | Value |
|---|---|
| Type | TXT |
| Host | _dmarc.dpsg-bodensee.de (update existing DMARC record) |
| Value | v=DMARC1; p=reject; rua=mailto:dmarc-reports@dpsg-bodensee.de |
CAA records specify which Certificate Authorities may issue certificates for your domain, reducing the risk of unauthorized certificate issuance.
| Field | Value |
|---|---|
| Type | CAA |
| Host | dpsg-bodensee.de (root of domain — adjust CA to match your provider) |
| Value | 0 issue "letsencrypt.org" |
MTA-STS enforces TLS encryption for inbound mail delivery, preventing downgrade attacks on your mail transport.
| Field | Value |
|---|---|
| Type | TXT |
| Host | _mta-sts.dpsg-bodensee.de (MTA-STS policy record) |
| Value | v=STSv1; id=dpsg-bodensee.de |
Email Security Methodology Can this domain be impersonated by email? Unlikely SPF and DMARC quarantine policy enforced
SPF Record RFC 7208 §4 Verified
SPF valid with industry-standard soft fail (~all), 3/10 lookups
DMARC Policy RFC 7489 §6.3 Verified
DMARC policy quarantine (100%) - good protection
pct= with t= (testing flag), add np= (non-existent subdomain policy), and mandate DNS tree walk for policy discovery instead of the Public Suffix List.DKIM Records RFC 6376 §3.6 Verified
Found DKIM for 3 selector(s) with strong keys (2048-bit)
l= tag body length vulnerability (attacker appends unsigned content to signed mail),
weak key exploitation (keys below 1024-bit are cryptographically breakable per RFC 6376 §3.3.3),
DKIM replay attacks (re-sending legitimately signed messages at scale)
MTA-STS RFC 8461 §3 Verified
MTA-STS in testing mode - TLS failures reported but not enforced
- Mode:
testing - Max Age: 7 days (604800 seconds)
- MX Patterns: mxe8db.netcup.net
MTA-STS policy enforcement is evaluated in Mail Transport Security below.
TLS-RPT RFC 8460 §3 Verified
TLS-RPT configured - receiving TLS delivery reports
DMARC External Reporting Authorization RFC 7489 §7.1
All 3 external reporting domains properly authorized
| External Domain | Authorization | Auth Record |
|---|---|---|
in.mailhardener.com |
Authorized |
v=DMARC1;
|
dmarc-reports.cloudflare.net |
Authorized |
v=DMARC1;
|
rua.dmarceye.com |
Authorized |
v=DMARC1
|
DANE / TLSA Verified Recon Methodology Can mail servers establish identity without a public CA? No
No DANE/TLSA records found (checked 2 MX hosts)
Two mechanisms protect email in transit. DANE is the primary standard; MTA-STS is the alternative for domains that cannot deploy DNSSEC:
- DNSSEC + DANE (RFC 7672) — Cryptographic chain of trust from DNS root to mail server certificate. Eliminates reliance on certificate authorities. No trust-on-first-use weakness. Requires DNSSEC.
- MTA-STS (RFC 8461) — HTTPS-based policy requiring TLS for mail delivery. Works without DNSSEC but relies on CA trust and is vulnerable on first use (§10). Created for domains where “deploying DNSSEC is undesirable or impractical” (§2).
Industry trend: Microsoft Exchange Online enforces inbound DANE with DNSSEC (GA October 2024), and providers like Proton Mail and Fastmail also support DANE. Google Workspace does not support DANE and relies on MTA-STS. Both mechanisms coexist because DANE is backward-compatible — senders skip the check if the domain isn't DNSSEC-signed (RFC 7672 §1.3).
Brand Security Can this brand be convincingly faked? Likely DMARC quarantine flags but does not reject spoofed mail (RFC 7489 §6.3) — no BIMI or CAA (RFC 8659) reinforcement leaves brand impersonation largely unaddressed
BIMI BIMI Spec Verified Warning
No valid BIMI record found
CAA RFC 8659 §4 Verified