Engineer's DNS Intelligence Report
The following DNS record TTLs deviate from recommended values. Incorrect TTLs can cause caching issues, slow propagation, or unnecessary DNS traffic.
| Record Type | Observed TTL | Typical TTL | Severity | Context |
|---|---|---|---|---|
| MX | 239s |
1 hour (3600s) |
high | MX TTL is below typical — observed 239s, 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 | 5 minutes (300s) |
1 hour (3600s) |
high | TXT 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 | 5 minutes (300s) |
1 hour (3600s) |
high |
AAAA 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.
Provider Note: This TTL (5 minutes (300s)) matches Cloudflare's fixed proxied-record TTL. If this record is proxied (orange cloud), the TTL is enforced by Cloudflare and cannot be changed. Disable proxying (gray cloud) to regain TTL control, at the cost of losing Cloudflare's DDoS protection and CDN.
|
| A | 5 minutes (300s) |
1 hour (3600s) |
high |
A 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.
Provider Note: This TTL (5 minutes (300s)) matches Cloudflare's fixed proxied-record TTL. If this record is proxied (orange cloud), the TTL is enforced by Cloudflare and cannot be changed. Disable proxying (gray cloud) to regain TTL control, at the cost of losing Cloudflare's DDoS protection and CDN.
|
| NS | 21539s |
1 day (86400s) |
medium | NS TTL is below typical — observed 21539s, 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. |
Big Picture Questions
- How often do you actually change this record? If it hasn’t changed in months, a short TTL is generating unnecessary DNS queries without any benefit.
- Are you preparing for a migration or IP change? Short TTLs make sense temporarily — but should be raised back to 1 hour (3600s) once the change is complete.
- Every DNS lookup adds 20–150ms of latency. With a 60s TTL, returning visitors trigger a fresh lookup every minute. With 3600s, they get cached responses for an hour — faster page loads, no extra infrastructure needed.
- Google runs A records at ~30s because they operate a global anycast network and need to steer traffic dynamically. For a typical website without that infrastructure, copying those TTLs increases query volume with zero upside.
chan.ns.cloudflare.com
2397075547
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.
| Parameter | Current | Suggested | Severity | Rationale |
|---|---|---|---|---|
| timeout_seconds | 5s |
8s |
low | Average scan duration is 36.8s, suggesting DNS responses are slow for this domain. Increasing timeout from 5s to 8s prevents premature resolution failures. RFC 8767 |
DNSSEC is not enabled for this domain. DNSSEC provides cryptographic authentication of DNS responses, preventing cache poisoning and DNS spoofing attacks.
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.theojouvin.com (update existing DMARC record) |
| Value | v=DMARC1; p=reject; rua=mailto:dmarc-reports@theojouvin.com |
CAA records specify which Certificate Authorities may issue certificates for your domain, reducing the risk of unauthorized certificate issuance.
| Field | Value |
|---|---|
| Type | CAA |
| Host | theojouvin.com (root of domain — adjust CA to match your provider) |
| Value | 0 issue "letsencrypt.org" |
TLS-RPT (TLS Reporting) sends you reports about TLS connection failures when other servers try to deliver mail to your domain.
| Field | Value |
|---|---|
| Type | TXT |
| Host | _smtp._tls.theojouvin.com (SMTP TLS reporting record) |
| Value | v=TLSRPTv1; rua=mailto:tls-reports@theojouvin.com |
MTA-STS enforces TLS encryption for inbound mail delivery, preventing downgrade attacks on your mail transport.
| Field | Value |
|---|---|
| Type | TXT |
| Host | _mta-sts.theojouvin.com (MTA-STS policy record) |
| Value | v=STSv1; id=theojouvin.com |
Email Security Methodology Can this domain be impersonated by email? Unlikely SPF and DMARC quarantine policy enforced
SPF Record RFC 7208 §4 Consistent
SPF valid with industry-standard soft fail (~all), 2/10 lookups
DMARC Policy RFC 7489 §6.3 Consistent
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 Consistent
Found DKIM records for 1 selector(s)
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)