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https://castbox.fm

Infrastructure

· 9 checks — DNS, redirects, IPv6, crawlability, URL variants, and domain intelligence rolled into one auditable list.
SCORE
88
GRADE
B
FIX
1
REVIEW
4
PASS
4
INFO
0
Probed from Madrid, Spain
200 OK
Checks
9
4 PASS 4 REVIEW 1 FIX
D
CDN & Delivery
Action
No CDN detected
FIX
No CDN detected
Warning::
No CDN detected
A CDN can significantly improve load times for users around the world by caching content at edge nodes closer to them.
No CDN detected

Consider using a CDN to improve global delivery speed and reduce origin load.

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.castbox.fm/
200https://castbox.fm/

Inconsistent — duplicate content risk

HTTP → HTTPS

301http://castbox.fm/ → https://castbox.fm/

Consistent

C
HTTP Probe Timing
Action
Total 1658 ms — DNS, TCP, TLS, TTFB, content transfer breakdown
REVIEW
DNS Lookup DNS Lookup — time to resolve the domain name to an IP address.
33 ms
TCP Connect TCP Connect — time to establish a TCP connection to the server.
224 ms
TLS Handshake TLS Handshake — time to complete the HTTPS encryption handshake.
450 ms
Time to First Byte Time to First Byte — how long the server takes to respond with the first byte of data.
1.43 s
Total Time Total request time from DNS lookup through full response.
1.66 s

Connection waterfall

DNS Lookup 33 ms TCP Connect 224 ms TLS Handshake 450 ms Server Processing 727 ms Content Transfer 225 ms
B
TLS Certificate Expiry & Recommendations
65 days until leaf cert expires — 4 issues to address
REVIEW

Certificate validity

65
days left
0d 30d 60d 90d+

Recommended actions

  • Prefer TLS 1.3 — TLS 1.2 is acceptable but TLS 1.3 removes RSA key exchange and improves latency
  • 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
2 A records, 37 ms lookup
PASS
2 A records, 37 ms lookup
Info::
Resolves to 2 IPv4 address(es)
Got: 13.193.228.58, 3.115.107.84
Info::
No IPv6 (AAAA) records
Info::
4 nameserver(s) configured
Got: ns-1860.awsdns-40.co.uk, ns-989.awsdns-59.net, ns-101.awsdns-12.com, ns-1323.awsdns-37.org
Info::
5 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: 37 ms
Got: 37 ms
A13.193.228.58, 3.115.107.84
AAAA—
CNAME—
NSns-1860.awsdns-40.co.uk, ns-989.awsdns-59.net, ns-101.awsdns-12.com, ns-1323.awsdns-37.org
MX
1 aspmx.l.google.com
5 alt2.aspmx.l.google.com
5 alt1.aspmx.l.google.com
10 alt4.aspmx.l.google.com
10 alt3.aspmx.l.google.com
TXT
SPF v=spf1 include:spf.zoho.com include:transmail.net include:servers.mcsv.net inclu...
google-site-verification=3mFzIfOXnoEMgL-JMulOFtrhLfDKswAipdTnIzUr1UE
google-site-verification=LQsnY64pPx4WMLgHyRgpi-qOH38IAfq6gsY2xUuJQ4s
google-site-verification=AUfrk7KKqihYAX7cD5TkHHSP2aJp2Y3nOU0TMVxqYKQ
google-site-verification=qRzbWr-3P6DqfeqQVl5vDuzJgeHV6zHaCnKhxEAUe7E
google-site-verification=5Vz4UGhank_MS0JCLzeIGqXwqYodxDcXfzHG2URnlRc
CAALookup not available with standard resolver
Resolved in 37 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
No redirects — direct access
PASS
No redirects — direct access
Info::
No redirects — direct access
Got: https://castbox.fm

https://castbox.fm

1148 ms · HTTP/1.1 FINAL

#URLStatusTimeProtocolServer
1https://castbox.fm2001148 msHTTP/1.1nginx
A+
Crawlability
robots.txt present, sitemap with 104 URLs
PASS
robots.txt present, sitemap with 104 URLs
Info::
robots.txt is present
Got: 408 bytes
Info::
sitemap.xml is present
Info::
sitemap.xml is valid XML
Info::
sitemap.xml contains 104 entries
Info::
Sitemap index with 104 child sitemaps
Info::
robots.txt does not reference a sitemap
Add a 'Sitemap:' directive to robots.txt so search engines can discover your sitemap.

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 408 B Sitemaps referenced 0 User-agents Googlebot, DuckDuckBot, Twitterbot, Bingbot, Facebot, * Blocking No — crawling allowed
User-agent: Googlebot
Allow: /
User-agent: DuckDuckBot
Allow: /
User-agent: Twitterbot
Allow: /
User-agent: Bingbot
Allow: /
User-agent: Facebot
Allow: /

User-agent: *
# Paths
Disallow: /login
Disallow: /creator
Disallow: /my
Disallow: /search?
# CSS, JS, Images
Disallow: .js$
Disallow: .css$
Disallow: .mp4$
Disallow: .mp3$
Disallow: .jpg$
Disallow: .jpeg$
Disallow: .gif$
Disallow: .png$
Disallow: .bmp$
sitemap.xml 200 OK
Type Sitemap Index URLs 104 entries Valid XML Yes
Child Sitemaps:
A+
Domain Intelligence
castbox.fm — via Instra Corporation Pty Ltd, 10 years, 5 months old, hosted on AWS
PASS
castbox.fm — via Instra Corporation Pty Ltd, 10 years, 5 months old, hosted on AWS
Info::
Domain registered until Jan 14, 2027 (8 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: Instra Corporation Pty 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: AWS
Got: AS16509
Domain expiry

182 days

January 14, 2027

SSL certificate

65 days

Issued by Amazon

Domain age

10 years, 5 months

Registered January 14, 2016

DNSSEC

Not enabled

Protects against DNS spoofing

Hosting

AWS

ASN AS16509

3.115.107.84

Registrar

Instra Corporation Pty Ltd

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 Instra Corporation Pty Ltd
Created January 14, 2016 (10 years, 5 months ago)
Expires January 14, 2027 (8 months)
Last Updated November 20, 2025
Name Servers ns-101.awsdns-12.com, ns-1323.awsdns-37.org, ns-1860.awsdns-40.co.uk, ns-989.awsdns-59.net
DNSSEC Not enabled
Hosting
IP Address 3.115.107.84
ASN AS16509 (AMAZON-02 - Amazon.com, Inc., US)
Provider AWS
Data source: rdap (0.4s)

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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