How to Fix Conflicting Server Name Error in Nginx

The conflicting server name error in Nginx happens when two or more server blocks use the same server_name. To fix it, ensure each server_name is unique or combine configurations if they should share the same name.

Why This Happens

This error occurs because Nginx requires each server_name to be unique across all server blocks. When two server blocks declare the same server_name, Nginx cannot decide which block to use for incoming requests, causing a conflict.

nginx

server {
    listen 80;
    server_name example.com;
    root /var/www/site1;
}

server {
    listen 80;
    server_name example.com;
    root /var/www/site2;
}

Output

nginx: [emerg] conflicting server name "example.com" on 0.0.0.0:80, ignored

The Fix

To fix the conflict, make sure each server_name is unique. If you want to serve the same domain with different settings, combine them into one server block or use different ports or IP addresses.

nginx

server {
    listen 80;
    server_name example.com;
    root /var/www/site1;
    # Add other settings here if needed
}

server {
    listen 80;
    server_name example.org;
    root /var/www/site2;
}

Output

nginx: configuration file /etc/nginx/nginx.conf test is successful

Prevention

To avoid this error in the future, always check your Nginx configuration files for duplicate server_name entries before restarting. Use tools like nginx -t to test configuration syntax. Organize your server blocks clearly and document domain assignments.

Related Errors

Other common Nginx errors include:

• Port conflicts: Multiple server blocks listening on the same port without proper differentiation.
• Duplicate listen directives: Overlapping listen directives causing binding errors.
• Missing root or index: Server blocks without a root directory or index file causing 404 errors.

Key Takeaways

Each server_name must be unique across all Nginx server blocks.

Use nginx -t to test configuration before restarting Nginx.

Combine server blocks if they share the same domain to avoid conflicts.

Organize and document your Nginx configurations clearly.

Check for other conflicts like ports and listen directives to prevent errors.