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Use when working with DNS records, propagation debugging, or domain routing
Install with Codex or Claude Copy this prompt, paste it into Codex, Claude, or another assistant, and let it review the skill page and install it for you.
Based on SOC occupation classification
| name | dns-and-domains |
| description | Use when working with DNS records, propagation debugging, or domain routing |
# Basic lookup
dig example.com
dig example.com A # A record (IPv4)
dig example.com AAAA # IPv6
dig example.com CNAME # CNAME
dig example.com MX # mail
dig example.com TXT # text records (SPF, DKIM, etc.)
dig example.com NS # nameservers
# Query a specific DNS server
dig @8.8.8.8 example.com
# Check propagation (query authoritative nameserver directly)
dig example.com NS # get nameservers
dig @<nameserver> example.com # query authoritative NS
# Reverse lookup (IP → hostname)
dig -x 1.2.3.4
| Symptom | Cause | Fix |
|---|---|---|
| NXDOMAIN | Record doesn't exist | Create the record |
| Old IP after update | TTL not expired yet | Wait, or lower TTL before changes |
| Works on some networks, not others | Propagation still in progress | Wait up to 48h |
| CNAME conflict | CNAME at root/apex (not allowed) | Use ALIAS/ANAME record instead |
| SSL cert error after DNS change | Old IP cached | Flush local DNS cache |
# Check from multiple locations
dig @8.8.8.8 example.com # Google
dig @1.1.1.1 example.com # Cloudflare
dig @9.9.9.9 example.com # Quad9
# Local DNS cache flush
# macOS
sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder
# Linux
sudo systemd-resolve --flush-caches
# Windows
ipconfig /flushdns
| Type | Use |
|---|---|
A | Maps hostname → IPv4 address |
AAAA | Maps hostname → IPv6 address |
CNAME | Alias of another hostname (not at root) |
MX | Mail server for the domain |
TXT | Text data — SPF, DKIM, verification tokens |
NS | Nameservers for the domain |
SOA | Start of authority — zone metadata |
PTR | Reverse DNS (IP → hostname) |
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