IP-based access control (allow/deny) in Nginx - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is IP-based access control in nginx?

It is a way to allow or deny access to a website or resource based on the visitor's IP address.

beginner

How do you allow access only from a specific IP address in nginx?

Use the directive allow [IP_address]; followed by deny all; to block others.

beginner

What does the directive deny all; do in nginx?

It blocks access to everyone except those explicitly allowed before it.

intermediate

Write a simple nginx config snippet to allow only 192.168.1.10 and deny all others.

location / { allow 192.168.1.10; deny all; }

intermediate

Can you allow multiple IP addresses in nginx? How?

Yes, by using multiple allow directives, one for each IP address or range.

Which nginx directive blocks all IPs except those allowed?

A reject all;

B allow all;

C block all;

D deny all;

The directive deny all; blocks all IPs except those explicitly allowed.

How do you allow access from IP 10.0.0.5 only?

A deny 10.0.0.5; allow all;

B allow 10.0.0.5; deny all;

C allow all; deny 10.0.0.5;

D deny all; allow 10.0.0.5;

You allow the specific IP first, then deny all others.

What happens if you only use deny all; without any allow?

A Blocks no one.

B Allows everyone to access.

C Blocks everyone from accessing.

D Allows only localhost.

Without any allow, deny all; blocks all access.

Can you allow an entire IP range in nginx?

A Yes, by specifying the range in CIDR notation in the allow directive.

B No, only single IPs are allowed.

C Yes, but only in the deny directive.

D No, nginx does not support IP ranges.

Nginx supports CIDR notation to allow or deny IP ranges.

Where in the nginx config do you place allow/deny directives?

A Inside a location, server, or http block.

B Only in the http block.

C Only in the server block.

D Only in the events block.

Allow and deny directives can be used inside location, server, or http blocks.

Explain how to restrict access to a website using IP addresses in nginx.

Think about allowing specific IPs first, then denying all others.

Describe how nginx handles multiple allow directives and what happens if no allow matches before deny all.

Consider how nginx processes access rules in order.