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https://nus.edu.sg

Infrastructure

· 9 checks — DNS, redirects, IPv6, crawlability, URL variants, and domain intelligence rolled into one auditable list.
SCORE
81
GRADE
B
FIX
0
REVIEW
6
PASS
3
INFO
0
Probed from Sao Paulo, Brazil
200 OK
Checks
9
3 PASS 6 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

C
Crawlability
Action
robots.txt present, sitemap with 0 URLs
REVIEW
robots.txt present, sitemap with 0 URLs
Info::
robots.txt is present
Got: 212 bytes
Info::
sitemap.xml is present
Warning::
sitemap.xml contains invalid XML
Search engines may not be able to parse the sitemap. Fix XML validation errors.
Warning::
sitemap.xml is empty — no URLs found
An empty sitemap provides no value. Add <url> entries for your pages.
Info::
robots.txt does not reference a sitemap
Add a 'Sitemap:' directive to robots.txt so search engines can discover your sitemap.

Search engines may not be able to parse the sitemap. Fix XML validation errors.

Why this matters

An unparseable sitemap is silently ignored by Google — the URLs it advertises are never queued for crawl.

Learn more ▾

Google's sitemap parser is strict about XML validity. A single unescaped `&` or unclosed tag invalidates the whole file. Run your sitemap through a validator (Search Console's Sitemaps report flags it) and fix the offending entry. Most generators escape correctly; mistakes usually come from manually-written entries.

Source: sitemaps.org / Google Search Central

An empty sitemap provides no value. Add <url> entries for your pages.

Why this matters

An empty sitemap signals 'no content to index' to Google — actively harmful versus having no sitemap at all.

Learn more ▾

Google compares URLs in the sitemap against URLs it has crawled. An empty sitemap on a site with thousands of pages signals abandonment. Either populate it correctly (most CMSes auto-generate) or delete the file and let Google crawl normally.

Source: Google Search Central / sitemaps.org

Add a 'Sitemap:' directive to robots.txt so search engines can discover your sitemap.

Why this matters

robots.txt omits Sitemap: directive — crawlers must fetch /sitemap.xml by convention; reliable but missing the explicit hint.

Source: sitemaps.org

robots.txt 200 OK
Size 212 B Sitemaps referenced 0 User-agents Blocking No — crawling allowed
<html>
<head>
<META NAME="robots" CONTENT="noindex,nofollow">
<script src="/_Incapsula_Resource?SWJIYLWA=5074a744e2e3d891814e9a2dace20bd4,719d34d31c8e3a6e6fffd425f7e032f3">
</script>
<body>
</body></html>
sitemap.xml 200 OK
Type URL Set URLs 0 entries Valid XML No
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.nus.edu.sg/
200https://nus.edu.sg/

Inconsistent — duplicate content risk

HTTP → HTTPS

301http://nus.edu.sg/ → https://nus.edu.sg/

Consistent

C
HTTP Probe Timing
Action
Total 1718 ms — DNS, TCP, TLS, TTFB, content transfer breakdown
REVIEW
DNS Lookup DNS Lookup — time to resolve the domain name to an IP address.
348 ms
TCP Connect TCP Connect — time to establish a TCP connection to the server.
1.12 s
TLS Handshake TLS Handshake — time to complete the HTTPS encryption handshake.
110 ms
Time to First Byte Time to First Byte — how long the server takes to respond with the first byte of data.
1.72 s
Total Time Total request time from DNS lookup through full response.
1.72 s

Connection waterfall

DNS Lookup 348 ms TCP Connect 1.12 s TLS Handshake 110 ms Server Processing 137 ms Content Transfer 0 ms
B
TLS Certificate Expiry & Recommendations
72 days until leaf cert expires — 3 issues to address
REVIEW

Certificate validity

72
days left
0d 30d 60d 90d+

Recommended actions

  • Add the preload directive and submit to hstspreload.org once max-age + includeSubDomains are in place
  • 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
B
CDN & Delivery
Incapsula
REVIEW
Incapsula
Info::
Site is served via Incapsula CDN
Got: x-iinfo: 10-2789564-0 0NNN RT(1776805772959 116) q(0 -1 -1 20) r(1 -1) B10(4,314,0) U18
CDN Detected: Incapsula
Provider Incapsula Evidence x-iinfo: 10-2789564-0 0NNN RT(1776805772959 116) q(0 -1 -1 20) r(1 -1) B10(4,314,0) U18
A
DNS Records
2 A records, 2816 ms lookup
PASS
2 A records, 2816 ms lookup
Info::
Resolves to 2 IPv4 address(es)
Got: 45.60.35.225, 45.60.33.225
Info::
No IPv6 (AAAA) records
Info::
4 nameserver(s) configured
Got: ns2.nus.edu.sg, dnssec1.singnet.com.sg, dnssec2.singnet.com.sg, ns1.nus.edu.sg
Info::
1 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
Warning::
DNS resolution is slow (2816 ms)
Slow DNS adds latency to every page load. Consider a faster DNS provider.
Got: 2816 ms
A45.60.35.225, 45.60.33.225
AAAA—
CNAME—
NSns2.nus.edu.sg, dnssec1.singnet.com.sg, dnssec2.singnet.com.sg, ns1.nus.edu.sg
MX
10 nus.in.tmes.trendmicro.com
TXT
docusign=b8333ad4-e528-4630-8b4b-bd2065b52b46
google-site-verification=fYmdBjdyYT7nwh5ibrrcoHTeXv00U-iuYHgbDP7toPU
tmes=ee68a6479a31be578e5ac3cf122cd3fb
amazonses:d/2nLTkfzbZowJ6WKliiHjIBLzYQfW7dokqJgWuYvCU=
amazonses:ZW5WU+BVqrNaP9NU2+qhUvKLdAYOkxWRuTJDksWHJi4=
autodesk-domain-verification=2w6hpfDHh3cHcT8KFNNi
MS=ms54785822
zYZWXv+CxwPReD66eS2JsSgYMnBLd9ZrohwexKj9tOngXz02egE9ovmmnt7pDRQm5HrAcR8pdEQ+XMKw...
adobe-idp-site-verification=37d46e00-e1af-41d1-bd95-4be77c6c386f
google-site-verification=8vQThrtwMAPQ6R2oUiFgOrSchO7eUVwm2Mt0WeYjouY
CT9/2y7bgJaXjgcaPyA+zpZw3qWQrzxGYZU+JSlLSTlHsQzCaInEaSBQBd7Zr1YSR3edLxyYbKN6P3Iv...
38v5jr3upts17ig3rlrj1ns570
stripe-verification=0D7EA3B255E84512DC6414721027729C3FCC725F42B87D403359781E884E...
cisco-ci-domain-verification=2f0dd8ae04758461a0d5c8648c0cb5099c087e54b72eaed4887...
globalsign-domain-verification=DE5B419BBE3C88E3FE38D34E6EB30597
globalsign-domain-verification=D404DFC41C5E080465CEDCC3AFDEA989
SPF v=spf1 a:spf-a.nus.edu.sg include:spf.protection.outlook.com include:spf.tmes.tr...
globalsign-domain-verification=B41AD3381E8BFC943122DD16698F3F76
openai-domain-verification=dv-8UDJ0WEioU0yFpgg0sJl2Nd3
ZOOM_verify_QNPVlabXLQrbEYZFmbejVg
MS=ms74561185
atlassian-domain-verification=rRxCwxtqnGriLha/ohMmedtQAPS8owxv0QzJbpIykp9evokbaF...
atlassian-domain-verification=3dXaB14bm126lrtqwwqFyhRMUu2CAPieUN03cgrluB6acyH3TG...
apple-domain-verification=EWXwi5Dv3Q6GcZjU
globalsign-domain-verification=ED031A4C750F0F2D59C7B33BB7493D57
globalsign-domain-verification=A297ED772E3FF3B0EFD32130CFADF18E
0AW81KJ8IXE96B27B4VU6U2EHGRW0VA3EJ2526Y7
vmware-cloud-verification-01dfd2de-6e71-4620-a028-7f3e879b93fa
globalsign-domain-verification=136b1ae71f68e55d955ca5ab91b68d47
google-site-verification=j6ODTDD1OC_6_UpEn2Db9TFlbEEZSaROd97tYvOy5Wc
openatts a=dns-did; p=did:ethr:0x253b74046d0d0d9efe214212f7900ae8b4f78f39#contro...
openatts net=ethereum netId=1 addr=0x66671988ee465b5c23Ef18838B32b1666d0EC8d6
pardot916111=a1203064fa45c6845eaed5c6de3c578b28337b32d280e791a80cedc03c530843
globalsign-domain-verification=818d17169a47f8120ac3e93dacfd3daa
CAALookup not available with standard resolver
Resolved in 2816 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.

Slow DNS adds latency to every page load. Consider a faster DNS provider.

Why this matters

DNS resolution is slow — anycast DNS providers (Cloudflare, Route 53) typically resolve <50ms globally.

Source: DNS performance benchmarks

A+
Redirect Chain
No redirects — direct access
PASS
No redirects — direct access
Info::
No redirects — direct access
Got: https://nus.edu.sg

https://nus.edu.sg

692 ms · HTTP/1.1 FINAL

#URLStatusTimeProtocolServer
1https://nus.edu.sg200692 msHTTP/1.1
A+
Domain Intelligence
nus.edu.sg — via Singnet Pte Ltd, 30 years old, hosted on INCAPSULA - Incapsula Inc, US
PASS
nus.edu.sg — via Singnet Pte Ltd, 30 years old, hosted on INCAPSULA - Incapsula Inc, US
Info::
Domain registered until Sep 2, 2026 (4 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: Singnet Pte Ltd
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: INCAPSULA - Incapsula Inc, US
Got: AS19551
Domain expiry

47 days

September 2, 2026

SSL certificate

72 days

Issued by GlobalSign nv-sa

Domain age

30 years

Registered September 2, 1996

DNSSEC

Not enabled

Protects against DNS spoofing

Hosting

INCAPSULA - Incapsula Inc, US

ASN AS19551

45.60.35.225

Registrar

Singnet Pte Ltd

Unlocked 5 NS records
Expiry timeline
Today
+1 year
Domain expiry SSL expiry Danger zone (≤30 days)
Recommended actions
  • Renew the domain or enable auto-renewal to prevent accidental expiry
  • Enable DNSSEC to protect visitors from DNS spoofing
  • Enable registrar lock (clientTransferProhibited) to block unauthorized domain transfers
Registrar Singnet Pte Ltd
Created September 2, 1996 (30 years ago)
Expires September 2, 2026 (4 months)
Last Updated October 2, 2025
Name Servers dnssec1.singnet.com.sg, dnssec2.singnet.com.sg, dnssec3.singnet.com.sg, ns1.nus.edu.sg, ns2.nus.edu.sg
DNSSEC Not enabled
Registrant NATIONAL UNIVERSITY OF SINGAPORE
Hosting
IP Address 45.60.35.225
ASN AS19551 (INCAPSULA - Incapsula Inc, US)
Provider INCAPSULA - Incapsula Inc, US
Data source: rdap (2.1s)

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

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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