Step-by-Step: Performing a CFi DNS Lookup to Diagnose Email and Website Issues

How to Use CFi DNS Lookup for Faster Domain Troubleshooting

1. When to use it

• Quickly check A/AAAA, CNAME, MX, NS, TXT, SOA, and other record types when a site, email, or service fails.
• Verify DNS propagation after changes.
• Confirm authoritative vs. cached responses.

2. Quick step-by-step (assumes CFi DNS Lookup web/CLI tool)

1. Enter the domain or hostname (e.g., example.com or mail.example.com).
2. Select the record type(s) to query (A, AAAA, CNAME, MX, TXT, NS, SOA, SRV, etc.).
3. Optionally choose a specific DNS server or the authoritative server to avoid cached results.
4. Run the lookup and review results: IPs for A/AAAA, targets and priority for MX, canonical names for CNAME, text for TXT/SPF/DMARC.
5. For propagation checks, repeat from different public resolvers (1.1.1.1, 8.8.8.8) or use the tool’s global-check option if available.

3. Troubleshooting checklist (use results to follow these)

• Site not reachable: confirm A/AAAA record exists and resolves to correct IP; check TTL and propagation.
• Wrong host: look for CNAME chains or conflicting A records.
• Email delivery issues: verify MX records and priorities, check SPF/DKIM/DMARC in TXT records.
• DNS mismatch across regions: query authoritative name servers directly; compare answers from multiple public resolvers.
• Missing records after change: verify TTL, query authoritative server, and wait full propagation window or clear caches where possible.
• DNSSEC failures: inspect RRSIG/DS records and chain of trust.

4. Advanced checks

• Query specific record type: run SRV for services, PTR for reverse lookups, TLSA for DANE.
• Use authoritative server queries or AXFR (if allowed) to view zone contents.
• Test from different geographic resolvers to detect regional caching issues.
• Compare SOA serial and TTL to determine if secondary servers are up to date.

5. Interpreting common outputs

• Multiple A records: load-balanced IPs — ensure all are correct and healthy.
• CNAME + A: final A/AAAA after following CNAME chain is authoritative answer.
• MX with no A for host: mail host must have A/AAAA record or be unreachable.
• NXDOMAIN: domain doesn’t exist — check spelling and registrar settings.
• SERVFAIL: resolver or authoritative server error — check DNS server health and DNSSEC.

6. Fast triage commands (local alternatives)

• dig example.com ANY +noall +answer
• dig @8.8.8.8 example.com MX +short
• nslookup -type=TXT example.com

7. Best practices

• Query authoritative name servers when confirming changes.
• Lower TTL temporarily before planned changes, then raise it afterward.
• Keep MX targets reachable with A/AAAA records.
• Monitor DNS records periodically and alert on unexpected changes.

If you want, I can run example dig/nslookup commands for a specific domain (I’ll assume example.com unless you provide one).