DNS and A Record Update Guide | Generated by AI
Great question! Let’s break down how domain resolution works, especially when you update A records with providers like GoDaddy, Namecheap, or Alibaba Cloud (Aliyun):
1. Domain Registration and Providers
- Domain Registrars (e.g., GoDaddy, Namecheap, Aliyun) are companies authorized to sell and manage domain names under generic top-level domains (gTLDs) like
.com,.ai,.net, etc. - When you buy a domain, you’re essentially leasing the right to use that name for a set period.
2. Updating A Records
- An A record maps a domain name to an IPv4 address.
- When you update the A record for your domain (e.g.,
example.com→192.0.2.1), you’re telling the DNS system: “When someone asks for this domain, send them to this IP address.”
3. How DNS Resolution Works
- User Request: Someone types
example.comin their browser. - Local DNS Resolver: Their device asks a local DNS resolver (usually provided by their ISP or a public DNS like Google’s 8.8.8.8).
- Root DNS Servers: If the resolver doesn’t know the IP, it asks the root DNS servers (there are 13 logical root servers globally, not 9). These don’t store domain IPs but direct the resolver to the correct TLD (Top-Level Domain) servers.
- TLD Servers: The resolver then asks the TLD servers (e.g.,
.com,.ai). These servers don’t know the IP either but direct the resolver to the authoritative DNS servers for your domain (managed by your registrar or hosting provider). - Authoritative DNS Servers: These servers hold the A record you updated. They return the IP address (e.g.,
192.0.2.1) to the resolver. - Response to User: The resolver caches the IP and sends it back to the user’s device, which then connects to the server at that IP.
4. Top-Level Domains (TLDs)
- There are over 1,500 TLDs (not just 9). The 9 you might be thinking of are likely the root DNS servers (labeled A-M), which are critical for DNS resolution but not TLDs themselves.
- TLDs include:
- Generic TLDs (gTLDs):
.com,.org,.net,.ai, etc. - Country-code TLDs (ccTLDs):
.uk,.jp,.cn, etc. - New gTLDs:
.app,.blog,.shop, etc.
- Generic TLDs (gTLDs):
5. Propagation
- When you update an A record, the change must propagate across all DNS servers worldwide. This can take minutes to 48 hours, depending on TTL (Time to Live) settings.
Key Takeaway
- Domain providers (registrars) manage your domain’s DNS records and communicate with TLD servers.
- Root DNS servers (13 logical clusters) guide resolvers to TLD servers.
- TLD servers direct resolvers to your domain’s authoritative DNS servers, where your A record is stored.
Would you like a diagram or further clarification on any step?