Infrastructure
· 9 checks — DNS, redirects, IPv6, crawlability, URL variants, and domain intelligence rolled into one auditable list.BDNS Records1 A records, 33 ms lookupREVIEW
| A | 23.195.97.15 |
| AAAA | 2a02:26f0:2380:28e::20b, 2a02:26f0:2380:281::20b |
| CNAME | www.comcast.com.edgekey.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.
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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.
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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.
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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 & Recommendations166 days until leaf cert expires — 2 issues to addressREVIEW
Certificate validity
Recommended actions
- Enable HSTS: Strict-Transport-Security: max-age=31536000; includeSubDomains
- Enable OCSP stapling on your TLS server to remove a CA roundtrip and protect user privacy
BCDN & DeliveryAkamaiREVIEW
ARedirect Chain1 redirect(s), 114 ms totalPASS
https://www.comcast.com
8 ms · HTTP/1.1
https://www.xfinity.com/
106 ms · HTTP/1.1 FINAL
| # | URL | Status | Time | Protocol | Server |
|---|---|---|---|---|---|
| 1 | https://www.comcast.com | 301 | 8 ms | HTTP/1.1 | AkamaiGHost |
| 2 | https://www.xfinity.com/ | 403 | 106 ms | HTTP/1.1 |
See the visual redirect chain in the HTTP Probe tab →
A+IPv6 ReadinessIPv6 reachable (1 ms)PASS
A+Crawlabilityrobots.txt present, sitemap with 274 URLsPASS
Add a 'Sitemap:' directive to robots.txt so search engines can discover your sitemap.
robots.txt omits Sitemap: directive — crawlers must fetch /sitemap.xml by convention; reliable but missing the explicit hint.
Source: sitemaps.org
# Comcast
# robots.txt for www.comcast.com
# Modified on 1/25/17
User-agent: *
Disallow:
A+URL Variantswww/non-www, trailing slash, HTTP→HTTPSPASS
www / non-www
HTTP → HTTPS
Consistent
A+Domain Intelligencecomcast.com — via CSC Corporate Domains, Inc., 31 years old, hosted on COMCAST-7922 - Comcast Cable Communications, LLC, USPASS
45 days
August 28, 2026
166 days
Issued by COMODO CA Limited
31 years
Registered August 29, 1995
Enabled
Protects against DNS spoofing
COMCAST-7922 - Comcast Cable Communications, LLC, US
ASN AS7922
96.99.227.0
CSC Corporate Domains, Inc.
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.
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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