Block an IP Address with Nginx | Hostvento Knowledge Base

Note: This guide needs root access. VPS and dedicated server customers have it. Shared hosting accounts do not.

What are these words?

An IP address is a number that identifies a computer on the internet. It works like a home address for a device.

Nginx (say "engine-x") is software that serves websites to visitors. You can tell it to refuse some visitors.

A wrong setting can stop Nginx from starting and take your site offline. Back up the file you edit. Also, never block your own IP address.

Connect to your server with SSH. SSH is a safe way to type commands on a remote computer.
Back up your site file. Replace example.com with your own file name.
```
cp /etc/nginx/conf.d/example.com.conf /etc/nginx/conf.d/example.com.conf.bak
```
This command makes a safe copy.
Open the file in an editor.
```
nano /etc/nginx/conf.d/example.com.conf
```
Find the server { ... } block.
Inside it, add one line for each address you want to block.
```
deny 203.0.113.5;
```
This blocks one address. The number here is only an example.
To block a whole range, use a slash.
```
deny 203.0.113.0/24;
```
If you want to allow everyone else, add this after the deny lines.
```
allow all;
```
Save the file. In nano, press Ctrl+O, Enter, then Ctrl+X.
Test your settings.
```
nginx -t
```
This checks for mistakes. Do not go on if it shows an error.
Reload Nginx.
```
systemctl reload nginx
```
This applies the change without stopping the site.

A blocked visitor sees a 403 Forbidden message. This means "you are not allowed in."

Remove the deny line, run nginx -t, then reload again.

Tip: Config file locations differ by setup. Some servers use /etc/nginx/sites-available/ instead of conf.d.