Limiting bandwidth must be done within a location directive. It's important to ensure that, if you have multiple location block directives which you want to limit, you need to adjust each of these. Here's our basic code:
server { listen 80; server_name limitbw.nginxcookbook.com; access_log /var/log/nginx/limitbw.log combined; location / { limit_rate 5m; root /var/www/html; index index.html index.htm; } }