How to Allow Specific IP in Nginx: Simple Guide

To allow a specific IP in nginx, use the allow directive with the IP address inside a location or server block, followed by deny all; to block others. This setup restricts access so only the specified IP can reach the site or resource.

Syntax

The allow directive specifies which IP addresses can access the resource. The deny directive blocks all other IPs not explicitly allowed. These directives are placed inside a server or location block in the Nginx configuration.

Example parts:

• allow 192.168.1.100; - permits this IP
• deny all; - blocks everyone else

nginx

location / {
    allow 192.168.1.100;
    deny all;
}

Example

This example shows how to allow only the IP 203.0.113.5 to access the entire website, while denying all other IPs.

nginx

server {
    listen 80;
    server_name example.com;

    location / {
        allow 203.0.113.5;
        deny all;
    }
}

Output

When a user from IP 203.0.113.5 visits example.com, they see the website normally.
Users from any other IP receive a 403 Forbidden error.

Common Pitfalls

Common mistakes include:

• Placing allow and deny outside server or location blocks, which makes them ineffective.
• Forgetting to reload or restart Nginx after changes, so new rules don't apply.
• Using incorrect IP formats or missing semicolons.
• Not ordering allow before deny, which can cause unexpected access results.

nginx

location / {
    deny all;
    allow 203.0.113.5;
}

# This will deny all, including the allowed IP, because deny comes first.

# Correct order:
location / {
    allow 203.0.113.5;
    deny all;
}

Quick Reference

Directive	Purpose	Example
allow	Permits access from specified IP or subnet	allow 192.168.0.1;
deny	Blocks access from specified IP or all	deny all;
location	Defines URL path to apply rules	location /admin/ { ... }
server	Defines virtual server block	server { listen 80; ... }

Key Takeaways

Use allow to specify permitted IPs and deny all; to block others.

Place allow and deny inside location or server blocks.

Always reload Nginx after configuration changes with nginx -s reload.

Order matters: allow directives must come before deny.

Check IP format carefully to avoid access issues.