Server Load Balancer:Add an HTTPS listener

Step 1: Configure a listener

1. Log on to the ALB console.
2. In the top navigation bar, select the region where the ALB instance is deployed.
3. Use one of the following methods to open the listener configuration wizard:
   • On the Instances page, find the ALB instance, and click Create Listener in the Actions column.
   • On the Instances page, click the ID of the ALB instance that you want to manage. On the Listener tab, click Create Listener.
4. In the Configure Listener step, set the following parameters and click Next.

   Parameter	Description
   Listener Protocol	Select the protocol of the listener. HTTPS is selected in this example.
   Listener Port	Enter the port on which the ALB instance listens. The ALB instance listens on the port and forwards requests to backend servers. 443 is entered in this example. In most cases, port 80 is used for HTTP and port 443 is used for HTTPS. Valid values: 1 to 65535. Note The ports on which an ALB instance listens must be unique.
   Listener Name	Enter a name for the listener. The name must be 2 to 256 characters in length and can contain letters, digits, periods (.), underscores (_), hyphens (-), commas (,), semicolons (;), forward slashes (/), and at signs (@).
   Advanced Settings	You can click Modify to configure the advanced settings.
   Enable HTTP/2	Specify whether to enable HTTP/2.
   Idle Connection Timeout Period	Specify a timeout period for idle connections. Unit: seconds. Valid values: 1 to 60. If no request is received within the specified timeout period, ALB closes the connection. When another request is received, ALB establishes a new connection. Note This feature is unavailable for HTTP/2 requests.
   Connection Request Timeout Period	Specify a request timeout period. Unit: seconds. Valid values: 1 to 180. If no response is received from the backend server within the request timeout period, ALB returns the HTTP 504 error code to the client.
   Compression	If you enable compression, files of specific types are compressed. If you disable compression, no file is compressed. All file types support Brotli compression. File types that support Gzip compression: text/xml, text/plain, text/css, application/javascript, application/x-javascript, application/rss+xml, application/atom+xml, application/xml, and application/json.
   Add HTTP Header Fields	Supported headers: X-Forwarded-For: retrieves client IP addresses. SLB-ID: retrieves the ID of the ALB instance. X-Forwarded-Proto: retrieves the listening protocol. X-Forwarded-Clientcert-subjectdn: retrieves information about the owner of the client certificate. X-Forwarded-Clientcert-issuerdn: retrieves information about the authority that issues the client certificate. X-Forwarded-Clientcert-fingerprint: retrieves the fingerprint of the client certificate. X-Forwarded-Clientcert-clientverify: retrieves the verification result of the client certificate. X-Forwarded-Port: retrieves the listening port. X-Forwarded-Client-srcport: retrieves the client port.
   QUIC Upgrade	Select whether to enable QUIC upgrade. To use this feature, you must select a QUIC listener from the Associate QUIC Listener drop-down list. If no QUIC listener is created, click Create Listener to create one. For more information, see Add a QUIC listener.

Step 2: Configure an SSL certificate

To create an HTTPS listener, you must configure an SSL certificate for identity authentication to ensure secure data transfer.

1. In the Configure SSL Certificates step, select a server certificate.
   If no server certificate is available, you can click Create Certificate in the drop-down list to go to the Certificate Management Service console. Then, you can purchase or upload a server certificate. For more information, see Purchase an SSL certificate and Upload an SSL certificate.
2. To enable mutual authentication or configure a TLS security policy, click Modify next to Advanced Settings.
3. Turn on Enable Mutual Authentication in the Advanced Settings section. Select Alibaba Cloud as the certificate source and select a CA certificate from the Default CA Certificate drop-down list.

   If no CA certificate is available, click Purchase CA Certificate to create one. For more information, see Purchase and enable a private CA.

   Note

   • Only standard and WAF-enabled ALB instances support mutual authentication. Basic ALB instances do not support mutual authentication.
   • If you want to disable mutual authentication after you enable this feature, perform the following operations:
     1. On the Instances page, click the ID of the ALB instance that you want to manage.
     2. On the Listener tab, click the ID of the HTTPS listener that you want to manage.
     3. On the Listener Details tab, disable mutual authentication in the SSL Certificate section.
4. Select a TLS security policy and click Next.
   If no TLS security policy is available, click Create TLS Security Policy to create one. For more information, see TLS security policies.

Step 3: Select a server group

In the Select Server Group step, select a server group, view the backend servers, and then click Next.

Step 4: Review the configuration

On the Confirm wizard page, confirm the configuration and click Submit.

FAQ

• What are the TLS versions supported by HTTPS listeners?

  HTTPS listeners support TLS 1.0, TLS 1.1, TLS 1.2, and TLS 1.3. For more information, see TLS security policies.

• Can backend servers retrieve the TLS version used by the associated HTTPS listener?

  Yes, backend servers can retrieve the TLS version used by the associated HTTPS listener.

• Which HTTP version is used by HTTPS listeners to distribute network traffic to backend servers?
  • If client requests use HTTP/1.1 or HTTP/2, Layer 7 listeners use HTTP/1.1 to distribute network traffic to backend servers.
  • If client requests use protocols other than HTTP/1.1 and HTTP/2, Layer 7 listeners use HTTP/1.0 to distribute network traffic to backend servers.