Proxy headers forwarding in Nginx - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of forwarding headers in an Nginx proxy setup?

Forwarding headers allows the proxy server to pass important client information, like the original IP address and protocol, to the backend server. This helps the backend understand the real client details.

beginner

Which Nginx directive is commonly used to forward the original client IP address to the backend?

The directive proxy_set_header X-Real-IP $remote_addr; forwards the client's IP address to the backend server.

intermediate

What does the X-Forwarded-For header represent in proxy forwarding?

It lists the IP addresses of the client and all proxies the request passed through, helping the backend identify the original client IP even behind multiple proxies.

beginner

How do you forward the original protocol (HTTP or HTTPS) in Nginx proxy headers?

Use proxy_set_header X-Forwarded-Proto $scheme; to forward the protocol used by the client to the backend server.

intermediate

Why is it important to set Host header when proxying requests in Nginx?

Setting proxy_set_header Host $host; ensures the backend server receives the original host requested by the client, which is important for virtual hosting and correct response generation.

Which directive forwards the client's IP address to the backend in Nginx?

A proxy_set_header X-Real-IP $remote_addr;

B proxy_pass http://backend;

C listen 80;

D server_name example.com;

The directive proxy_set_header X-Real-IP $remote_addr; forwards the client's IP address to the backend server.

What does the header X-Forwarded-For contain?

A The client's browser type

B Only the backend server IP

C The client's IP and all proxy IPs the request passed through

D The server's hostname

X-Forwarded-For contains the original client IP and all proxy IPs the request passed through.

How do you forward the original protocol (HTTP or HTTPS) in Nginx proxy headers?

A proxy_pass http://backend;

B proxy_redirect off;

C listen 443 ssl;

D proxy_set_header X-Forwarded-Proto $scheme;

proxy_set_header X-Forwarded-Proto $scheme; forwards the original protocol used by the client.

Why set the Host header in proxy forwarding?

A To block unwanted hosts

B To pass the original requested hostname to the backend

C To change the backend IP

D To enable SSL

Setting the Host header passes the original hostname requested by the client to the backend.

Which header is NOT typically forwarded by Nginx proxy to preserve client info?

A Server-Timing

B X-Forwarded-For

C X-Forwarded-Proto

D X-Real-IP

Server-Timing is not typically forwarded to preserve client info; it relates to server performance metrics.

Explain why forwarding headers like X-Real-IP and X-Forwarded-For is important in an Nginx proxy setup.

Think about how the backend knows who really made the request.

Describe how to configure Nginx to forward the original client IP, protocol, and host headers to the backend server.

Focus on the proxy_set_header lines needed.