Default server handling in Nginx - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of the 'default_server' directive in nginx?

The 'default_server' directive marks a server block as the default to handle requests that do not match any other server_name. It ensures nginx knows which server block to use when no specific match is found.

beginner

How do you specify a default server for HTTP traffic in nginx?

You add 'default_server' to the listen directive, for example: listen 80 default_server; This tells nginx to use this server block as the default for port 80.

intermediate

What happens if no default_server is set in nginx and a request does not match any server_name?

Nginx will use the first server block defined for that listen port as the default. This can lead to unexpected behavior if you don't explicitly set a default server.

intermediate

Can you have multiple default servers for the same port in nginx?

No, only one server block per listen port can be marked as 'default_server'. Trying to set multiple default servers for the same port will cause nginx to fail to start.

intermediate

How does nginx decide which server block to use when a request comes in?

Nginx first matches the request's IP and port to a listen directive. Then it matches the Host header to server_name. If no match, it uses the default_server for that listen port.

Which directive marks a server block as the default in nginx?

A server_default

B default_server

C default_block

D server_main

The 'default_server' directive is used in the listen directive to mark a server block as the default.

What happens if no 'default_server' is set and a request does not match any server_name?

A Nginx returns an error

B Nginx ignores the request

C Nginx uses the first server block for that port

D Nginx redirects to a default page

Nginx uses the first server block defined for the listen port as the default if no 'default_server' is set.

How do you set a server block as default for HTTPS on port 443?

A listen 443;

B server_name default 443;

C default_server 443;

D listen 443 default_server;

You add 'default_server' to the listen directive like 'listen 443 default_server;' to set it as default for HTTPS.

Can you have two server blocks with 'default_server' on the same port?

A No, nginx will fail to start

B Yes, nginx will load balance

C Yes, but only one will respond

D No, but nginx will ignore one

Only one server block per port can be 'default_server'. Multiple defaults cause nginx startup failure.

What does nginx use to match incoming requests to server blocks?

A IP, port, and server_name

B Port only

C IP address only

D server_name only

Nginx matches requests by IP and port (listen directive) and then by server_name.

Explain how nginx decides which server block handles a request when multiple server blocks exist.

Think about the order nginx uses to find the right server block.

Describe how to configure a default server in nginx and why it is important.

Focus on the 'listen' directive and request routing.