Infrastructure
· 9 checks — DNS, redirects, IPv6, crawlability, URL variants, and domain intelligence rolled into one auditable list.BTLS Certificate Expiry & Recommendations157 days until leaf cert expires — 2 issues to addressREVIEW
Certificate validity
Recommended actions
- Submit your domain to hstspreload.org to be added to the Chrome preload list
- Enable OCSP stapling on your TLS server to remove a CA roundtrip and protect user privacy
BCDN & DeliveryGoogle Cloud CDNREVIEW
A+DNS Records1 A records, 197 ms lookupPASS
| A | 34.107.134.59 |
| AAAA | 2600:1901:0:c831:: |
| CNAME | — |
| NS | ns-cloud-d1.googledomains.com, ns-cloud-d2.googledomains.com, ns-cloud-d3.googledomains.com, ns-cloud-d4.googledomains.com |
| MX | 10 nihcesxway4.hub.nih.gov 10 nihcesxway3.hub.nih.gov 10 nihcesxway5.hub.nih.gov |
| TXT | o6lmcbo4cn7r8882vn65cpjcfv. SPF v=spf1 include:nih.gov ~all google-site-verification=PNIgJgOfWG3Bog_wPM4sYF_UW_QJ0T-JVZHEDuDCaD4 google-site-verification=fOlJTfzhsN7Vee2dbKTOV2EleNnSVtj2RYj6BaQezbY GrclYGeUpoKjW0RtHDm8IoEXyQddPqL5pdiiXvLuV7za7OiNXC+wgFWXKhBJGAt5m6Qx3pTXVsPlpI18... |
| 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
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.
A+Redirect ChainNo redirects — direct accessPASS
https://clinicaltrials.gov
243 ms · HTTP/1.1 FINAL
| # | URL | Status | Time | Protocol | Server |
|---|---|---|---|---|---|
| 1 | https://clinicaltrials.gov | 200 | 243 ms | HTTP/1.1 | istio-envoy |
A+IPv6 ReadinessIPv6 reachable (2 ms)PASS
A+Crawlabilityrobots.txt present, sitemap with 2 URLsPASS
User-agent: *
Disallow: /api/
# Allow access to the internal API to let SPA function properly
Allow: /api/int/
Allow: /api/seo/
Disallow: /search?
Disallow: /expert-search?
# this is ported from 'classic' site
# Some docs say must be a whole number of seconds.
# Crawlers differ whether this means delay-between-calls or whether it is max-requests-in-window.
# Google ignore this value, but supposedly honored by yandex and bing.
Crawl-delay: 1
Sitemap: https://clinicaltrials.gov/assets/sitemap.xml
A+URL Variantswww/non-www, trailing slash, HTTP→HTTPSPASS
www / non-www
Preferred variant: non-www
HTTP → HTTPS
Consistent
A+Domain Intelligenceclinicaltrials.gov — via get.gov, 26 years, 7 months oldPASS
34 days
August 18, 2026
157 days
Issued by GoDaddy.com, Inc.
26 years, 7 months
Registered February 3, 2000
Enabled
Protects against DNS spoofing
Unknown
2600:1901:0:c831::
get.gov
Expiry timeline
Recommended actions
- Renew the domain or enable auto-renewal to prevent accidental expiry
- Enable registrar lock (clientTransferProhibited) to block unauthorized domain transfers
The domain can be transferred without an unlock step. Enable registrar lock (clientTransferProhibited) in your registrar's control panel to protect against unauthorized or accidental transfers.
Without registrar lock, an attacker who phishes your registrar credentials can transfer the domain in minutes — total brand hijack.
Learn more ▾ ▴
Registrar lock (clientTransferProhibited, clientUpdateProhibited, clientDeleteProhibited) requires extra verification before any transfer/update/delete. Every major registrar offers it free. Combined with 2FA on your registrar account, it's the strongest defense against domain hijacking.
Source: ICANN / domain-security best practice