Guides Hub

DNS

DNS_PROBE_FINISHED_NXDOMAIN Fix Checklist

DNS_PROBE_FINISHED_NXDOMAIN? Fix it in 4 checks: DNS records, nameserver delegation, resolver cache, domain status. Free instant check, no sign-up.

DNS

SPF Permerror: Too Many DNS Lookups

SPF permerror? Get under the 10 DNS lookup limit in 3 steps: count lookups, flatten includes, drop dead mechanisms. Free instant check, no sign-up.

HTTP

ERR_TOO_MANY_REDIRECTS: Find and Break the Redirect Loop

ERR_TOO_MANY_REDIRECTS? Locate the loop in 4 checks: origin rules, CDN settings, cookies, HTTPS enforcement. Free instant redirect trace, no sign-up.

SSL

SSL Certificate Expired: Renewal and Recovery Checklist

SSL certificate expired or expiring? Recover in 4 steps: renew, deploy to every endpoint, verify the chain, automate. Free instant check, no sign-up.

RDAP / WHOIS

RDAP vs WHOIS: Key Differences

RDAP vs WHOIS: structured JSON vs legacy text, what each returns, and when WHOIS is still required. Free instant RDAP domain lookup, no sign-up.

General

Site Unreachable? DNS, SSL, and HTTP Diagnostic Checklist

Site unreachable? Isolate the failing layer in a fixed order: DNS first, then SSL, then HTTP. One free instant check runs all three, no sign-up.

Domain does not resolve

Use DNS, propagation, and nameserver guides to separate record errors from cache delays.

Mail delivery or auth fails

Trace SPF, DMARC, blacklist, and DNS issues before changing mail infrastructure.

HTTPS or certificate warning

Check expiry, SAN mismatch, wildcard coverage, and certificate chain issues.

Redirect loop or access failure

Start with redirect behavior, response codes, and broad DNS/HTTP diagnosis guides.

4 guides

DNS Lookup

4 guides

Deliverability

4 guides

SSL Check

4 guides

HTTP Diagnostics

4 guides

RDAP / WHOIS

4 guides

Propagation

4 guides

Port Scan

2026-09-18

HTTP Error 403.14 - Forbidden: IIS Directory Listing

HTTP Error 403.14 - Forbidden on IIS: fix it in 3 checks — default document, extensionless routing, and the 404 it hides. Free instant check, no sign-up.

2026-09-18

TXT Record for Domain Ownership Verification

TXT record for domain ownership verification: where the token goes, root vs host, and the deletion trap that unverifies you. Free instant check, no sign-up.

2026-09-17

Error 1018 Unable to Resolve (Cloudflare): Fix

Error 1018 means Cloudflare can't apply your zone's config at the edge — a recent activation or a ghost partner zone, not a record you fix. Free instant check, no sign-up.

2026-09-17

DKIM Record Setup and Check (DNS TXT)

DKIM record setup and check: publish the selector._domainkey TXT, avoid the two-record split trap, and confirm the key resolves. Free instant check, no sign-up.

2026-09-16

Error 1013: HTTP Hostname and TLS SNI Mismatch (Fix)

Error 1013 means your TLS SNI and HTTP Host header disagree. Fix in 3 checks: client SNI, SSL-proxy networks, and custom Host overrides. Free instant check.

2026-09-16

Dothome Domain Not Connecting? Fix DNS & Nameservers

Dothome domain not connecting after a nameserver change? Check registrar NS, A/CNAME, and propagation in 4 steps to find the broken layer. Free instant check.