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DNS Overview
DNS (Domain Name System) is the technology that maps human-readable domain names to machine-readable IP addresses. When you request a website, your browser initiates a DNS query. This query is typically handled by a recursive resolver, which may contact:
- The root nameserver
- The TLD (Top-Level Domain) nameserver
- The authoritative nameserver
...if the answer isn’t already cached.
DNS Records
DNS records are used to define how a domain behaves. A complete DNS configuration often involves multiple record types. Common attributes include:
- Host Name: The subdomain or prefix, such as
www. - IP Address or URL: The target IP address or domain (e.g. for CNAME records).
- TTL (Time to Live): How long the record is cached by resolvers.
- Record Type: The function of the record, e.g.
CNAME,A.
Common DNS Record Types
- A – Maps a domain to an IPv4 address.
- AAAA – Maps a domain to an IPv6 address. Note: Not supported on Esadax.
- ALIAS – Similar to
CNAME, but can be used at the zone apex. - CAA – Specifies which Certificate Authorities can issue certificates. Esadax automatically adds CAA records for Let's Encrypt.
- CNAME – Points a domain to another domain name. Cannot be used at the zone apex.
- HTTPS – A secure variant of
CNAME, usable at the zone apex. Includes metadata like ALPN protocols.
💡 DNS Propagation isn’t a record type, but rather the process of DNS changes spreading across the internet.
DNS Propagation
The time it takes for DNS changes to propagate can vary. Most Esadax records propagate fully within 60 seconds, but external resolvers and ISPs may cache longer.
Best Practices for DNS Changes
- ✅ Review existing DNS records before switching providers.
- ⏱ Lower TTL values to
60saround 24 hours in advance of changes. - 🔍 Use tools like WhatsMyDNS.net to track global propagation.
- 🔁 Only update production-critical records after propagation is confirmed.
Troubleshooting DNS Issues
If something isn’t working as expected, check for:
- ❌ Misconfigured record values
- ⏳ TTLs that are too high, delaying propagation
- 🔁 Recursive CNAME loops
- 📉 Incomplete propagation
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