CNAME Configuration

CNAME Configuration

CNAME (Canonical Name) records are used to point your domain to Sundun's CDN network. This guide explains how to configure CNAME records for optimal performance and security.

Understanding CNAME Records

A CNAME record creates an alias from your domain to Sundun's edge servers. When a user visits your website, DNS resolution directs them to the nearest Sundun Point of Presence (PoP).

User Request → DNS Lookup → CNAME Resolution → Sundun Edge → Origin Server

Getting Your CNAME Target

After adding a domain to Sundun, you'll receive a unique CNAME target:

1. Go to Domains in your dashboard
2. Select your domain
3. Navigate to DNS Settings
4. Copy your CNAME target (format: example-com.Sundun.net)

Configuring CNAME Records

For Subdomains (www, api, cdn, etc.)

Add a CNAME record in your DNS provider:

Example DNS Configuration:

www.example.com. 300 IN CNAME example-com.Sundun.net. api.example.com. 300 IN CNAME example-com.Sundun.net. cdn.example.com. 300 IN CNAME example-com.Sundun.net.

For Root/Apex Domains

Root domains (example.com without www) cannot use standard CNAME records due to DNS RFC restrictions. Use one of these alternatives:

Option 1: CNAME Flattening (Recommended)

Some DNS providers support CNAME-like functionality at the apex:

Option 2: Use Sundun DNS

Transfer your DNS to Sundun for full apex domain support:

1. Go to DNS Management in your dashboard
2. Click Enable Sundun DNS
3. Update your domain's nameservers to:

- ns1.Sundun.com

- ns2.Sundun.com

Option 3: A Record with Anycast IPs

Use Sundun's Anycast IP addresses (Enterprise only):

example.com. 300 IN A 198.51.100.1 example.com. 300 IN A 198.51.100.2

Note: Contact support to obtain Anycast IPs for your account.

Verifying CNAME Configuration

Using Command Line

# Check CNAME record dig www.example.com CNAME # Expected output ;; ANSWER SECTION: www.example.com. 300 IN CNAME example-com.Sundun.net. # Verify resolution dig www.example.com A # Should resolve to Sundun edge IPs

Using Online Tools

• DNS Checker - Check global propagation
• MXToolbox - DNS lookup and diagnostics

From Sundun Dashboard

1. Go to Domains → Select your domain
2. Click Verify DNS
3. The system will check your CNAME configuration

DNS Propagation

DNS changes can take time to propagate globally:

Tips for faster propagation:

1. Lower your TTL to 300 before making changes
2. Wait for the old TTL to expire
3. Make the CNAME change
4. Verify propagation across multiple regions

Multiple CNAME Targets

For advanced configurations, you may need different CNAME targets:

Common Issues

CNAME Conflict with MX Records

If you have email on the same subdomain:

# This will NOT work - CNAME conflicts with MX mail.example.com CNAME example-com.Sundun.net mail.example.com MX mailserver.example.com # Solution: Use a different subdomain for CDN cdn.example.com CNAME example-com.Sundun.net

CNAME Chain Too Long

Avoid creating CNAME chains:

# Bad - creates a chain www.example.com → alias.example.com → example-com.Sundun.net # Good - direct CNAME www.example.com → example-com.Sundun.net

SSL Certificate Errors After CNAME

If you see certificate errors:

1. Ensure HTTPS certificates are configured in Sundun
2. Wait for certificate provisioning (up to 15 minutes)
3. Check that the certificate covers your domain

Best Practices

1. Use low TTLs initially: Set TTL to 300 when first configuring
2. Test before going live: Use staging subdomains first
3. Monitor after changes: Check your dashboard for traffic patterns
4. Keep DNS records documented: Maintain a record of all DNS configurations
5. Use DNSSEC: Enable DNSSEC for additional security (if supported)

API Reference

Configure CNAME settings via API:

# Get CNAME target for a domain curl -X GET https://api.Sundun.com/v1/domains/example.com/dns \ -H "Authorization: Bearer YOUR_API_KEY" # Response { "cname_target": "example-com.Sundun.net", "status": "active", "verification": "verified" }

Need help with DNS configuration? Contact support@Sundun.com