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https://udacity.com

Infrastructure

· 9 checks — DNS, redirects, IPv6, crawlability, URL variants, and domain intelligence rolled into one auditable list.
SCORE
87
GRADE
B
FIX
0
REVIEW
3
PASS
6
INFO
0
Probed from Madrid, Spain
301 Moved Permanently
Checks
9
6 PASS 3 REVIEW
C
IPv6 Readiness
Action
No IPv6 support
REVIEW
No IPv6 support
Info::
No IPv6 (AAAA) records found
IPv6 support is increasingly important for global accessibility. About 40% of internet users have IPv6 connectivity.
No IPv6 Support
About 40% of internet users have IPv6. Consider adding AAAA records.

IPv6 support is increasingly important for global accessibility. About 40% of internet users have IPv6 connectivity.

Why this matters

No AAAA records — same impact as 'no IPv6 (AAAA) records'; IPv6-preferring clients pay extra latency falling back to IPv4.

Source: Google IPv6 stats

B
URL Variants
www/non-www, trailing slash, HTTP→HTTPS
REVIEW
www/non-www, trailing slash, HTTP→HTTPS
Critical::
Both www and non-www versions serve content
Got: Both variants return 200 Expected: One variant 301-redirects to the other
Info::
HTTP correctly 301-redirects to HTTPS

www / non-www

200https://www.udacity.com/
200https://udacity.com/

Inconsistent — duplicate content risk

HTTP → HTTPS

301http://udacity.com/ https://udacity.com/

Consistent

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

Certificate validity

148
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+
DNS Records
4 A records, 28 ms lookup
PASS
4 A records, 28 ms lookup
Info::
Resolves to 4 IPv4 address(es)
Got: 13.33.243.119, 13.33.243.128, 13.33.243.92, 13.33.243.88
Info::
No IPv6 (AAAA) records
Info::
4 nameserver(s) configured
Got: ns-1109.awsdns-10.org, ns-1014.awsdns-62.net, ns-13.awsdns-01.com, ns-1549.awsdns-01.co.uk
Info::
2 mail exchanger(s) configured
Info::
CAA records not checked
CAA record lookup requires a specialized DNS resolver. This check will be available in a future update.
Info::
SPF record present in TXT
Info::
DNS resolution time: 28 ms
Got: 28 ms
A13.33.243.119, 13.33.243.128, 13.33.243.92, 13.33.243.88
AAAA
CNAME
NSns-1109.awsdns-10.org, ns-1014.awsdns-62.net, ns-13.awsdns-01.com, ns-1549.awsdns-01.co.uk
MX
10 mxa-00593801.gslb.pphosted.com
10 mxb-00593801.gslb.pphosted.com
TXT
status-page-domain-verification=y08j3wqb2sw9
atlassian-sending-domain-verification=4a498916-8f31-4a42-b4ec-758ee24b79e4
google-site-verification=FJqQiq8r-ExkN9kiVDy44SL2wkm6VS8zka0HUkunGME
atlassian-domain-verification=mBjfUMIIMEpsVsE5wql1jKvzxVpCWKZwpnSWFbY51pnIrp5nSd...
atlassian-domain-verification=59aeShSTbEvs7cB33k4Wsvath8fOirTAy79UnAbOloto0AyhJb...
SPF v=spf1 include:_spf.google.com include:sendgrid.net include:mail.zendesk.com inc...
cursor-domain-verification-7zn380=ChGiB1Fhp14asve0cCXYyhxFn
apple-domain-verification=iaobRRgsJ5xUkcuj
facebook-domain-verification=q0sgl66mvrtj3ivlf1s98bn6gxvii2
CAALookup not available with standard resolver
Resolved in 28 ms

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.

A
Redirect Chain
1 redirect(s), 130 ms total
PASS
1 redirect(s), 130 ms total
Info::
Single redirect
Got: https://udacity.com → https://www.udacity.com/ (301)
Info::
WWW normalization redirect

https://udacity.com

7 ms · HTTP/1.1

301

https://www.udacity.com/

124 ms · HTTP/1.1 FINAL

#URLStatusTimeProtocolServer
1https://udacity.com3017 msHTTP/1.1AmazonS3
2https://www.udacity.com/200124 msHTTP/1.1cloudflare

See the visual redirect chain in the HTTP Probe tab →

A+
Crawlability
robots.txt present, sitemap with 178 URLs
PASS
robots.txt present, sitemap with 178 URLs
Info::
robots.txt is present
Got: 1131 bytes
Info::
sitemap.xml is present
Info::
sitemap.xml is valid XML
Info::
sitemap.xml contains 178 entries
Info::
robots.txt references sitemap
robots.txt 200 OK
Size 1131 B Sitemaps referenced 2 User-agents Applebot-Extended, * Blocking No — crawling allowed
# Applebot-Extended
User-agent: Applebot-Extended
Disallow: /

# *
User-agent: *
Allow: /
Disallow: /blog/wp-admin/admin-ajax.php
Disallow: /blog/wp-admin/options-general.php
Disallow: /blog/wp-admin/themes.php
Disallow: /blog/wp-admin/load-scripts.php
Disallow: /blog/wp-admin/upload.php
Disallow: /blog/wp-admin/load-styles.php
Disallow: /blog/wp-admin/plugins.php
Disallow: /blog/wp-admin/admin.php
Disallow: /blog/wp-admin/post.php
Disallow: /*?price
Disallow: /*?search
Disallow: /*?coupon
Disallow: /*?promo
Disallow: /*?checkoutType
Disallow: /*?school
Disallow: /*?skill
Disallow: /*?difficulty
Disallow: /*?duration
Disallow: /*?type
Disallow: /dashboard
Disallow: /settings/*
Disallow: /quick-checkout*
Disallow: /checkout/*
Disallow: /assessment/*
Disallow: /org/*
Disallow: /enrollment/*
Disallow: /flag/*
Disallow: /test/*
Disallow: /masters-artificial-intelligence/student-guide
Disallow: /mba-ai-product-management/student-guide
Disallow: /resources/*
Disallow: /*/404

# Host
Host: https://www.udacity.com

# Sitemaps
Sitemap: https://www.udacity.com/sitemap.xml
Sitemap: https://www.udacity.com/server-sitemap.xml

A+
Domain Intelligence
udacity.com — via CSC Corporate Domains, Inc., 14 years, 5 months old, hosted on AWS
PASS
udacity.com — via CSC Corporate Domains, Inc., 14 years, 5 months old, hosted on AWS
Info::
Domain registered until Jan 17, 2028 (1 years, 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: CSC Corporate Domains, Inc.
Warning::
Registrar lock is NOT enabled
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.
Info::
Hosting: AWS
Got: AS16509
Domain expiry

582 days

January 17, 2028

SSL certificate

148 days

Issued by Amazon

Domain age

14 years, 5 months

Registered January 17, 2012

DNSSEC

Not enabled

Protects against DNS spoofing

Hosting

AWS

ASN AS16509

13.33.243.128

Registrar

CSC Corporate Domains, Inc.

Unlocked 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
  • Enable registrar lock (clientTransferProhibited) to block unauthorized domain transfers
Registrar CSC Corporate Domains, Inc.
Created January 17, 2012 (14 years, 5 months ago)
Expires January 17, 2028 (1 years, 9 months)
Last Updated March 23, 2026
Name Servers ns-1014.awsdns-62.net, ns-1109.awsdns-10.org, ns-13.awsdns-01.com, ns-1549.awsdns-01.co.uk
DNSSEC Not enabled
Hosting
IP Address 13.33.243.128
ASN AS16509 (AMAZON-02 - Amazon.com, Inc., US)
Provider AWS
Data source: rdap (0.3s)

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

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.

Why this matters

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

A+
HTTP Probe Timing
Total 53 ms — DNS, TCP, TLS, TTFB, content transfer breakdown
PASS
DNS Lookup DNS Lookup — time to resolve the domain name to an IP address.
48 ms
TCP Connect TCP Connect — time to establish a TCP connection to the server.
1 ms
TLS Handshake TLS Handshake — time to complete the HTTPS encryption handshake.
3 ms
Time to First Byte Time to First Byte — how long the server takes to respond with the first byte of data.
53 ms
Total Time Total request time from DNS lookup through full response.
53 ms

Connection waterfall

DNS Lookup 48 ms TCP Connect 1 ms TLS Handshake 3 ms Server Processing 2 ms Content Transfer 0 ms
A+
CDN & Delivery
AWS CloudFront (Hit from cloudfront)
PASS
AWS CloudFront (Hit from cloudfront)
Info::
Site is served via AWS CloudFront CDN (edge: MAD53-P5)
Got: x-amz-cf-id: uNwPd9jMS1di_M2e7HHum_tpkFLGlL0sJstxcIdI0cid0JXBmunVrA==
Info::
CDN cache status: Hit from cloudfront
CDN Detected: AWS CloudFront
Provider AWS CloudFront Cache Status Hit from cloudfront Evidence x-amz-cf-id: uNwPd9jMS1di_M2e7HHum_tpkFLGlL0sJstxcIdI0cid0JXBmunVrA==
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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