Infrastructure
· 9 checks — DNS, redirects, IPv6, crawlability, URL variants, and domain intelligence rolled into one auditable list.DCDN & DeliveryActionNo CDN detectedFIX
Consider using a CDN to improve global delivery speed and reduce origin load.
BDNS Records1 A records, 18 ms lookupREVIEW
| A | 192.0.66.20 |
| AAAA | 2a04:fa87:fffd::c000:4214 |
| CNAME | harvard-edu.go-vip.net |
| NS | — |
| MX | — |
| TXT | — |
| CAA | Lookup not available with standard resolver |
Multiple A records provide failover if one server goes down.
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.
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.
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'.
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)
BTLS Certificate Expiry & Recommendations59 days until leaf cert expires — 3 issues to addressREVIEW
Certificate validity
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 ChainNo redirects — direct accessPASS
https://www.harvard.edu
17 ms · HTTP/1.1 FINAL
| # | URL | Status | Time | Protocol | Server |
|---|---|---|---|---|---|
| 1 | https://www.harvard.edu | 200 | 17 ms | HTTP/1.1 | nginx |
A+IPv6 ReadinessIPv6 reachable (2 ms)PASS
A+Crawlabilityrobots.txt present, sitemap with 5 URLsPASS
# START YOAST BLOCK
# ---------------------------
User-agent: *
Disallow:
Sitemap: https://www.harvard.edu/sitemap_index.xml
Sitemap: https://www.harvard.edu/president/sitemap_index.xml
Sitemap: https://www.harvard.edu/media-relations/sitemap_index.xml
Sitemap: https://www.harvard.edu/climate-and-sustainability/sitemap_index.xml
Sitemap: https://www.harvard.edu/wellbeing/sitemap_index.xml
Sitemap: https://www.harvard.edu/guidelines/sitemap_index.xml
Sitemap: https://www.harvard.edu/ai/sitemap_index.xml
Sitemap: https://www.harvard.edu/community/sitemap_index.xml
Sitemap: https://legacyofslavery.harvard.edu/sitemap_index.xml
Sitemap: https://www.harvard.edu/federal-lawsuits/sitemap_index.xml
# ---------------------------
# END YOAST BLOCK
A+URL Variantswww/non-www, trailing slash, HTTP→HTTPSPASS
www / non-www
Preferred variant: www
HTTP → HTTPS
Consistent
A+Domain Intelligenceharvard.edu — 41 years, 4 months old, hosted on WordPress.com (Automattic)PASS
EXPIRED
July 31, 2026
59 days
Issued by Let's Encrypt
41 years, 4 months
Registered June 27, 1985
Status unknown
Protects against DNS spoofing
WordPress.com (Automattic)
ASN AS2635
192.0.66.20
Registrar unknown
Expiry timeline
Recommended actions
- Domain has EXPIRED — renew immediately to avoid total site outage