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Infrastructure

· 9 checks — DNS, redirects, IPv6, crawlability, URL variants, and domain intelligence rolled into one auditable list.
SCORE
95
GRADE
A
FIX
0
REVIEW
2
PASS
7
INFO
0
Probed from Singapore, Singapore
302 Found
Checks
9
7 PASS 2 REVIEW
B
DNS Records
1 A records, 128 ms lookup
REVIEW
1 A records, 128 ms lookup
Info::
Resolves to 1 IPv4 address(es)
Got: 151.101.77.91
Info::
Single A record — no DNS redundancy
Multiple A records provide failover if one server goes down.
Info::
Has 1 IPv6 (AAAA) record(s)
Got: 2a04:4e42:12::347
Warning::
CNAME record at zone apex
A CNAME at the zone apex can break MX and NS records. Use ALIAS/ANAME or A records instead.
Got: mozilla.map.fastly.net
Info::
No NS records found
Info::
No MX records — email not configured via DNS
Info::
CAA records not checked
CAA record lookup requires a specialized DNS resolver. This check will be available in a future update.
Info::
No SPF record found in TXT records
SPF helps prevent email spoofing. Add a TXT record starting with 'v=spf1'.
Info::
DNS resolution time: 128 ms
Got: 128 ms
A151.101.77.91
AAAA2a04:4e42:12::347
CNAMEmozilla.map.fastly.net
NS—
MX—
TXT—
CAALookup not available with standard resolver
Resolved in 128 ms

Multiple A records provide failover if one server goes down.

Why this matters

Single A record means a single point of failure — if that IP goes down, your site is unreachable until DNS TTL expires.

Learn more ▾

Add multiple A records for round-robin failover, or use a managed DNS provider with health-checked failover (Route 53, Cloudflare, NS1). Short TTL (60-300s) lets clients recover faster on outages.

Source: SRE practice / DNS architecture

A CNAME at the zone apex can break MX and NS records. Use ALIAS/ANAME or A records instead.

Why this matters

CNAME at the apex (example.com) breaks every other apex record (MX, TXT, NS) — DNS-protocol violation per RFC 1034.

Learn more ▾

RFC 1034 forbids CNAME alongside other records at the same name. Some DNS providers offer ALIAS / ANAME / flattened-CNAME records that work around this — use those instead. Otherwise apex-level CNAME breaks email (no MX), domain ownership verification (no TXT), and more.

Source: RFC 1034

CAA record lookup requires a specialized DNS resolver. This check will be available in a future update.

Why this matters

Informational: CAA (Certification Authority Authorization) records weren't checked in this scan.

SPF helps prevent email spoofing. Add a TXT record starting with 'v=spf1'.

Why this matters

Without SPF, receiving servers can't validate sending IPs — your domain is easier to spoof in phishing.

Learn more ▾

SPF complements DMARC. Both should be published. SPF records list authorized sending IPs (e.g., `v=spf1 include:_spf.google.com ~all` for Google Workspace). After publishing, verify in Google Postmaster Tools or mxtoolbox.

Source: RFC 7208 (SPF)

B
TLS Certificate Expiry & Recommendations
81 days until leaf cert expires — 3 issues to address
REVIEW

Certificate validity

81
days left
0d 30d 60d 90d+

Recommended actions

  • Enable HSTS: Strict-Transport-Security: max-age=31536000; includeSubDomains
  • Enable DNSSEC on your domain for DNS spoofing protection
  • Enable OCSP stapling on your TLS server to remove a CA roundtrip and protect user privacy
A+
Redirect Chain
No redirect data available
PASS
No redirect data available
Info::
No redirect data captured
A+
IPv6 Readiness
IPv6 reachable (41 ms)
PASS
IPv6 reachable (41 ms)
Info::
IPv6 is configured and reachable at 2a04:4e42:12::347
Got: 41 ms connect
IPv6 Ready
AAAA Records 2a04:4e42:12::347 Connection Reachable (41 ms)
A+
Crawlability
robots.txt present, sitemap with 10 URLs
PASS
robots.txt present, sitemap with 10 URLs
Info::
robots.txt is present
Got: 119 bytes
Info::
sitemap.xml is present
Info::
sitemap.xml is valid XML
Info::
sitemap.xml contains 10 entries
Info::
Sitemap index with 10 child sitemaps
Info::
robots.txt references sitemap
robots.txt 200 OK
Size 119 B Sitemaps referenced 1 User-agents * Blocking No — crawling allowed
User-agent: *
Sitemap: https://developer.mozilla.org/sitemap.xml

Disallow: /api/
Disallow: /*/files/
Disallow: /media
sitemap.xml 200 OK
Type Sitemap Index URLs 10 entries Valid XML Yes
Child Sitemaps:
A+
URL Variants
www/non-www, trailing slash, HTTP→HTTPS
PASS
www/non-www, trailing slash, HTTP→HTTPS
Info::
HTTP correctly 301-redirects to HTTPS

www / non-www

https://www.developer.mozilla.org/
200https://developer.mozilla.org/

HTTP → HTTPS

301http://developer.mozilla.org/ → https://developer.mozilla.org/

Consistent

A+
Domain Intelligence
mozilla.org — via MarkMonitor Inc., 28 years, 7 months old
PASS
mozilla.org — via MarkMonitor Inc., 28 years, 7 months old
Info::
Domain registered until Jan 23, 2027 (9 months remaining)
Info::
DNSSEC is not enabled
DNSSEC protects against DNS spoofing attacks. While not required, enabling DNSSEC adds an additional layer of security. Contact your DNS provider to enable it.
Info::
Registrar: MarkMonitor Inc.
Domain expiry

159 days

January 23, 2027

SSL certificate

81 days

Issued by Let's Encrypt

Domain age

28 years, 7 months

Registered January 24, 1998

DNSSEC

Not enabled

Protects against DNS spoofing

Hosting

Unknown

Registrar

MarkMonitor Inc.

Lock status unknown 4 NS records
Expiry timeline
Today
+1 year
Domain expiry SSL expiry Danger zone (≤30 days)
Recommended actions
  • Enable DNSSEC to protect visitors from DNS spoofing
Registrar MarkMonitor Inc.
Created January 24, 1998 (28 years, 7 months ago)
Expires January 23, 2027 (9 months)
Last Updated December 27, 2024
Name Servers ns1-240.akam.net, ns4-64.akam.net, ns5-65.akam.net, ns7-66.akam.net
DNSSEC Not enabled
Data source: rdap (10.0s)

DNSSEC protects against DNS spoofing attacks. While not required, enabling DNSSEC adds an additional layer of security. Contact your DNS provider to enable it.

Why this matters

Without DNSSEC, an attacker who can poison your DNS can hijack your domain — and SSL certs alone don't stop them.

Learn more ▾

DNSSEC adds cryptographic signatures to DNS records, preventing forged responses from poisoning resolver caches. Without it, an attacker who controls the network path can redirect your domain to a malicious server before any HTTPS handshake happens. Most modern registrars (Cloudflare, Google Domains, Route 53) enable it with one toggle.

Source: ICANN / RFC 4033

A+
HTTP Probe Timing
Total 338 ms — DNS, TCP, TLS, TTFB, content transfer breakdown
PASS
DNS Lookup DNS Lookup — time to resolve the domain name to an IP address.
42 ms
TCP Connect TCP Connect — time to establish a TCP connection to the server.
35 ms
TLS Handshake TLS Handshake — time to complete the HTTPS encryption handshake.
38 ms
Time to First Byte Time to First Byte — how long the server takes to respond with the first byte of data.
339 ms
Total Time Total request time from DNS lookup through full response.
339 ms

Connection waterfall

DNS Lookup 42 ms TCP Connect 35 ms TLS Handshake 38 ms Server Processing 224 ms Content Transfer 0 ms
A
CDN & Delivery
Fastly (MISS, MISS, MISS)
PASS
Fastly (MISS, MISS, MISS)
Info::
Site is served via Fastly CDN
Got: x-served-by: cache-sin-wsss1830085-SIN, cache-sin-wsss1830036-SIN, cache-hkg17920-HKG
Info::
CDN cache status: MISS, MISS, MISS
CDN Detected: Fastly
Provider Fastly Cache Status MISS, MISS, MISS Evidence x-served-by: cache-sin-wsss1830085-SIN, cache-sin-wsss1830036-SIN, cache-hkg17920-HKG
All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.

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