HTTP/2 configuration in Nginx - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is HTTP/2 and why is it important in web servers like nginx?

HTTP/2 is a newer version of the HTTP protocol that makes websites load faster by allowing multiple requests at the same time over one connection. It improves speed and efficiency compared to HTTP/1.1.

beginner

How do you enable HTTP/2 in an nginx server block?

Add the keyword http2 to the listen directive in your server block, for example:
listen 443 ssl http2;

intermediate

Why must SSL/TLS be enabled to use HTTP/2 in nginx?

Most browsers require HTTP/2 to run over a secure connection (HTTPS). So nginx must have SSL/TLS configured to use HTTP/2.

intermediate

What is the purpose of the ssl_certificate and ssl_certificate_key directives in nginx HTTP/2 configuration?

They specify the paths to your SSL certificate and private key files. These files enable encrypted connections needed for HTTP/2.

beginner

How can you verify that HTTP/2 is working on your nginx server?

Use browser developer tools or online tools to check the protocol used. You can also run curl -I --http2 https://yourdomain.com to see if HTTP/2 is active.

Which directive enables HTTP/2 in an nginx server block?

A http2_enable on;

B enable_http2 true;

C listen 443 ssl http2;

D protocol http2;

The correct way to enable HTTP/2 is by adding 'http2' to the listen directive, like 'listen 443 ssl http2;'.

Why is SSL/TLS required for HTTP/2 in nginx?

A Because browsers require HTTP/2 over secure connections

B Because HTTP/2 only works on port 80

C Because nginx does not support HTTP/2 without SSL

D Because SSL/TLS speeds up HTTP/2

Browsers require HTTP/2 to be used over HTTPS, so SSL/TLS must be enabled.

Which command can you use to check if your nginx server supports HTTP/2?

A nginx -t --http2

B curl -I --http2 https://yourdomain.com

C curl --http1.1 https://yourdomain.com

D nginx -v http2

The curl command with --http2 option checks if the server supports HTTP/2.

What files must be specified to enable SSL for HTTP/2 in nginx?

A ssl_key and ssl_cert

B http2_certificate and http2_key

C tls_certificate and tls_key

D ssl_certificate and ssl_certificate_key

The directives ssl_certificate and ssl_certificate_key specify the SSL certificate and key files.

What is a main benefit of HTTP/2 over HTTP/1.1?

A Allows multiple requests over one connection

B Uses less secure connections

C Requires more server memory

D Only works with IPv6

HTTP/2 allows multiplexing multiple requests on a single connection, improving speed.

Explain how to configure HTTP/2 in nginx including SSL setup.

Think about the server block and secure connection requirements.

Describe how you can verify that HTTP/2 is active on your nginx server.

Use simple command line tools or browser features.

Practice

1. What is the correct way to enable HTTP/2 in an nginx server block?

easy

A. Add http2 to the location block

B. Add http2 to the server_name directive

C. Add http2 to the listen directive with SSL enabled

D. Add http2 to the root directive

Solution

1. Step 1: Understand HTTP/2 enabling in nginx

   HTTP/2 is enabled by adding the http2 parameter to the listen directive, which must be used with SSL (HTTPS).

2. Step 2: Identify correct directive usage

   The http2 parameter does not belong in server_name, root, or location blocks.

3. Final Answer:

   Add http2 to the listen directive with SSL enabled -> Option C

4. Quick Check:

   Enable HTTP/2 by adding http2 to listen with SSL [OK]

Hint: Add 'http2' only in listen directive with SSL [OK]

Common Mistakes:

• Adding http2 to server_name or root directives
• Forgetting to enable SSL when using http2
• Placing http2 inside location blocks

2. Which of the following is the correct syntax to enable HTTP/2 on port 443 in nginx?

easy

A. listen 443 ssl;

B. listen http2 443 ssl;

C. listen 443 http2;

D. listen 443 ssl http2;

Solution

1. Step 1: Review nginx listen directive syntax

   The correct order is listen [port] ssl http2; to enable SSL and HTTP/2 on the port.

2. Step 2: Check each option

   listen 443 ssl http2; uses correct syntax: listen 443 ssl http2;. listen http2 443 ssl; reverses order but is invalid. listen 443 ssl; misses http2. listen 443 http2; misses ssl, which is required for http2.

3. Final Answer:

   listen 443 ssl http2; -> Option D

4. Quick Check:

   Correct syntax is 'listen 443 ssl http2;' [OK]

Hint: Use 'listen 443 ssl http2;' exactly for HTTP/2 [OK]

Common Mistakes:

• Omitting ssl when enabling http2
• Placing http2 before ssl in listen directive
• Using http2 without SSL on port 443

3. Given this nginx server block snippet, what will happen when a client connects?

server {
    listen 443 ssl http2;
    ssl_certificate /etc/ssl/cert.pem;
    ssl_certificate_key /etc/ssl/key.pem;
    server_name example.com;
}

medium

A. The server will accept HTTPS connections using HTTP/2 protocol

B. The server will accept HTTP connections only, no HTTP/2

C. The server will reject connections due to missing http2 directive

D. The server will accept HTTPS but use HTTP/1.1 only

Solution

1. Step 1: Analyze listen directive

   The listen directive includes ssl and http2, enabling HTTPS with HTTP/2 support.

2. Step 2: Confirm SSL certificates presence

   SSL certificate and key files are specified, so HTTPS can work properly.

3. Final Answer:

   The server will accept HTTPS connections using HTTP/2 protocol -> Option A

4. Quick Check:

   listen with ssl and http2 means HTTPS + HTTP/2 enabled [OK]

Hint: ssl + http2 in listen means HTTPS with HTTP/2 [OK]

Common Mistakes:

• Assuming HTTP/2 works without ssl
• Confusing HTTP and HTTPS ports
• Ignoring the http2 parameter in listen

4. You added http2 to your nginx listen directive but HTTP/2 is not working. Which configuration mistake could cause this?

medium

A. Forgetting to enable SSL (missing ssl in listen directive)

B. Using http2 in the server_name directive

C. Setting listen to port 80 with http2

D. Adding http2 inside the location block

Solution

1. Step 1: Understand HTTP/2 requirements in nginx

   HTTP/2 requires SSL (HTTPS) to be enabled in nginx; without ssl in the listen directive, HTTP/2 won't work.

2. Step 2: Evaluate other options

   Options A, C, and D are invalid uses of http2 but the main cause is missing SSL.

3. Final Answer:

   Forgetting to enable SSL (missing ssl in listen directive) -> Option A

4. Quick Check:

   HTTP/2 needs SSL enabled in listen directive [OK]

Hint: Always include ssl with http2 in listen directive [OK]

Common Mistakes:

• Not enabling ssl with http2
• Placing http2 in wrong directives
• Trying http2 on port 80 without ssl

5. You want to configure nginx to serve HTTP/2 on port 443 and redirect all HTTP (port 80) traffic to HTTPS. Which configuration snippet correctly achieves this?

hard

A. server {
listen 80 http2;
return 301 https://$host$request_uri;
}

server {
listen 443 ssl;
server_name example.com;
}

B. server {
listen 80;
return 301 https://$host$request_uri;
}

server {
listen 443 ssl http2;
ssl_certificate /etc/ssl/cert.pem;
ssl_certificate_key /etc/ssl/key.pem;
server_name example.com;
}

C. server {
listen 443 ssl http2;
server_name example.com;
}

server {
listen 80 ssl http2;
return 301 https://$host$request_uri;
}

D. server {
listen 443 ssl;
ssl_certificate /etc/ssl/cert.pem;
ssl_certificate_key /etc/ssl/key.pem;
server_name example.com;
}

server {
listen 80;
return 301 https://$host$request_uri;
}

Solution

1. Step 1: Redirect HTTP to HTTPS on port 80

   The first server block listens on port 80 without SSL and redirects all requests to HTTPS using a 301 redirect.

2. Step 2: Enable HTTPS with HTTP/2 on port 443

   The second server block listens on port 443 with ssl and http2 enabled, and specifies SSL certificates.

3. Step 3: Verify other options

   server {
       listen 80 http2;
       return 301 https://$host$request_uri;
   }
   
   server {
       listen 443 ssl;
       server_name example.com;
   }

   incorrectly enables http2 on port 80 (no SSL).

   server {
       listen 443 ssl http2;
       server_name example.com;
   }
   
   server {
       listen 80 ssl http2;
       return 301 https://$host$request_uri;
   }

   enables SSL and http2 on port 80 which is invalid.

   server {
       listen 443 ssl;
       ssl_certificate /etc/ssl/cert.pem;
       ssl_certificate_key /etc/ssl/key.pem;
       server_name example.com;
   }
   
   server {
       listen 80;
       return 301 https://$host$request_uri;
   }

   misses http2 on port 443.

4. Final Answer:

   The configuration correctly redirects HTTP to HTTPS and enables HTTP/2 on HTTPS -> Option B

5. Quick Check:

   Redirect HTTP on 80, enable SSL+http2 on 443 [OK]

Hint: Redirect HTTP on 80, enable SSL+http2 on 443 [OK]

Common Mistakes:

• Enabling http2 on port 80 without SSL
• Missing http2 on HTTPS server block
• Not redirecting HTTP to HTTPS properly