When setting up a website, you'll often need to handle both the root domain (example.com) and its www subdomain (www.example.com). The DNS system treats these as distinct entities, which leads to the common question: Do we need separate records for each?

Many developers initially try using a wildcard record:

*.example.com   3600    A   0   192.1.2.3

While this catches all subdomains, it doesn't cover the root domain. Conversely, a root record:

example.com     3600    A   0   192.1.2.3

won't automatically include the www subdomain.

The most reliable approach is using two separate records:

example.com     3600    A   0   192.1.2.3
www.example.com 3600    A   0   192.1.2.3

This ensures both domain variations resolve correctly. However, there's a more maintainable alternative.

For better maintainability, consider:

example.com     3600    A     0   192.1.2.3
www.example.com 3600    CNAME example.com

This configuration has several advantages:

• Single IP address management (change only the A record)
• Follows common web hosting practices
• Reduces potential DNS propagation issues

Here's how this would look in a BIND zone file:

$ORIGIN example.com.
@       3600    IN    A     192.1.2.3
www     3600    IN    CNAME @

The @ symbol represents the root domain, making the configuration more readable.

Remember to:

• Set proper TTL values (3600 seconds is common)
• Configure your web server to handle both domains
• Implement proper redirects (usually root → www or www → root)
• Consider using a CDN which might require different DNS setups

After making changes, verify with:

dig example.com A +short
dig www.example.com A +short

Both should return your server's IP address (or the CNAME should resolve correctly).

When setting up DNS records for a website, developers often encounter this dilemma: how to properly configure records to serve both www-prefixed and bare domain versions of the site. The root issue stems from how DNS wildcards work versus explicit records.

# Problem scenario 1 - Wildcard only
*.example.com   3600    A   0   192.1.2.3
# example.com won't resolve because wildcards don't cover the bare domain

# Problem scenario 2 - Bare domain only
example.com     3600    A   0   192.1.2.3
# www.example.com won't resolve without specific record

There is no single record type that can handle both cases simultaneously. You must use either:

# Option 1: Dual A records
example.com     3600    A   0   192.1.2.3
www.example.com 3600    A   0   192.1.2.3

# Option 2: A + CNAME (preferred)
example.com     3600    A   0   192.1.2.3
www.example.com 3600    CNAME example.com.

The CNAME method provides several technical advantages:

• Single point of IP address management (change only the A record)
• Proper alignment with HTTP redirect strategies
• Better DNS cache behavior
• Cleaner infrastructure as you scale

Here's how this would look in various DNS management systems:

# AWS Route 53 example
{
  "ResourceRecordSets": [
    {
      "Name": "example.com",
      "Type": "A",
      "TTL": 300,
      "ResourceRecords": [{"Value": "192.1.2.3"}]
    },
    {
      "Name": "www.example.com",
      "Type": "CNAME",
      "TTL": 300,
      "ResourceRecords": [{"Value": "example.com"}]
    }
  ]
}

# DigitalOcean DNS example
; A Records
@   3600    IN    A    192.1.2.3
www 3600    IN    CNAME    example.com.

For production environments, consider these additional factors:

• Always set up corresponding HTTPS records (use Let's Encrypt's DNS-01 challenge)
• Implement proper TTL values (lower for staging, higher for production)
• Configure appropriate redirects at the web server level (301 from www to bare or vice versa)
• Set up DNSSEC where applicable