Adding an HTTPS Listener

Scenarios

You can add an HTTPS listener if you require encrypted transmission. Load balancers decrypt HTTPS requests before routing them to backend servers. Once the servers process the requests, they send them back to the load balancers for encryption. Finally, the load balancers send the encrypted requests to the clients.

When you add an HTTPS listener, ensure that the backend subnet of the load balancer has sufficient IP addresses. If the IP addresses are insufficient, add more subnets on the summary page of the load balancer. After you select a subnet, do not configure network ACL rules for this subnet. If rules are configured, access to the load balancer may be denied.

Constraints

• If the listener protocol is HTTPS, the backend protocol can be HTTP or HTTPS.
• If you only select the network load balancing type for your dedicated load balancer, you cannot add HTTPS listeners to this load balancer.

Procedure

1. Go to the load balancer list page.
2. On the displayed page, locate the load balancer and click its name.
3. On the Listeners tab, click Add Listener. Configure the parameters based on Table 1.

   Table 1 Parameters for configuring an HTTPS listener

   Parameter	Description
   Frontend Protocol	Specifies the protocol that will be used by the load balancer to receive requests from clients. Select HTTPS.
   Listening Port	Specifies the port that will be used by the load balancer to receive requests from clients. The port number ranges from 1 to 65535.
   Name (Optional)	Specifies the listener name.
   QUIC	Specifies whether to upgrade HTTPS to QUIC. When adding an HTTPS listener, you can select a QUIC listener to route requests. Upgrading HTTPS to QUIC lowers latency and speeds up communication, particularly in poor networks with high latency.
   Transfer Client IP Address	This option is enabled for dedicated load balancers by default. When you use an HTTPS listener to forward requests, you can use the X-Forwarded-For header to transfer client IP addresses. The first IP address recorded in the X-Forwarded-For header is the client IP address. For details, see Using Dedicated Load Balancers to Transfer Client IP Address.
   Advanced Forwarding	Specifies whether to enable advanced forwarding. This option allows you to configure advanced forwarding policies to forward requests to different backend server groups. For more information, see Advanced Forwarding.
   Access Control	Specifies how access to the listener is controlled. For details, see What Is Access Control? All IP addresses is selected for access control by default. You can select Whitelist or Blacklist and choose an IP address group. Whitelist: Only IP addresses in the whitelist can access the listener. Requests from the IP addresses or CIDR blocks specified in the IP address group will be forwarded by the listener. Blacklist: IP addresses in the blacklist are not allowed to access the listener. Requests from the IP addresses or CIDR blocks specified in the IP address group will not be forwarded by the listener.
   Configure Certificate
   SSL Authentication	Specifies whether how you want the clients and backend servers to be authenticated. One-way authentication: Backend servers will be authenticated by clients. Mutual authentication: The clients and backend servers will authenticate each other.
   CA Certificate	Specifies the certificate that will be used to authenticate the client when SSL Authentication is set to Mutual authentication and the frontend protocol is HTTPS. CA certificates are also called client CA public key certificate. They are used to verify the issuer of a client certificate. HTTPS connections can only be established when the client provides a certificate issued by a specific CA.
   Server Certificate	Specifies a server certificate that will be used to authenticate the server when HTTPS is used as the frontend protocol. Both the certificate and private key are required.
   SNI	Specifies whether to enable SNI. Server Name Indication (SNI) is an extension to TLS. It allows clients to specify which domain name of a listener they are trying to connect in the first request. Once receiving the request, the load balancer searches for the certificate based on the domain name. The client includes the domain name in the initial SSL handshake. Once receiving the request, the load balancer searches for the certificate based on the domain name. If an SNI certificate is found, this certificate will be used for authentication. If no SNI certificates are found, the server certificate is used for authentication. For details, see Using SNI Certificates for Access Through Multiple Domain Names.
   SNI Certificate	Specifies one or more certificates associated with the domain name when the frontend protocol is HTTPS and SNI is enabled. You can only select the server certificate with SNI domain names. For details, see Using SNI Certificates for Access Through Multiple Domain Names.
   More (Optional)
   Security Policy	Specifies the security policy you can use if you select HTTPS as the frontend protocol. For more information, see Configuring TLS Security Policies for Encrypted Communication.
   0-RTT	Specifies whether to enable 0-RTT data transmission to reduce the request response duration. 0-RTT data transmission can be enabled only when the security policy supports TLS 1.3. If this option is enabled, replay attacks may occur. NOTE: This option is available in certain regions. You can see which regions support this option on the console.
   HTTP/2	Specifies whether you want to use HTTP/2 if you select HTTPS for Frontend Protocol. For details, see Enabling HTTP/2 for Faster Communication.
   Data Compression	Specifies whether to enable the data compression option. If you do not enable this option, files will not be compressed. Brotli and Gzip can compress the files in the following format: text/html, tex/xml, text/plain text/css, application/javascript, application/x-javascript, application/rss+xml, application/atom+xml, application/xml, and application/json. NOTE: This option is available in certain regions. You can see which regions support this option on the console.
   Retry on Other Backend Servers	Specifies whether to allow the load balancer to attempt to establish connections with other backend servers in the same backend server group, if it fails to connect to a backend server. If all four retries fail, error code 502 or 504 will be returned. Connection error: If the load balancer cannot connect to a backend server due to an error, such as a failed or rejected connection, error code 502 will be returned. Request timeout: If the backend server does not respond within the timeout duration, error code 504 will be returned. Connection timeout: The load balancer attempts to connect to a backend server but fails within the timeout duration. Response timeout: The load balancer has sent a request to a backend server but does not receive a response within the timeout duration. Note: If there is an error after the load balancer forwards a request using a non-idempotent request method, such as POST, PATCH, or DELETE, the load balancer will not resend the request. NOTE: This option is available in certain regions. You can see which regions support this option on the console.
   Idle Timeout (s)	Specifies the length of time for a connection to keep alive, in seconds. If no request is received within this period, the load balancer closes the connection and establishes a new one with the client when the next request arrives. The idle timeout duration ranges from 0 to 4000.
   Request Timeout (s)	Specifies the length of time (in seconds) that a load balancer is willing to wait for a client request to finish. The load balancer terminates the connection if a request takes too long to complete. The request timeout duration ranges from 1 to 300.
   Response Timeout (s)	Specifies the length of time (in seconds) after which the load balancer sends a 504 Gateway Timeout error to the client if the load balancer receives no response from the backend server after routing a request to the backend server and receives no response after attempting to route the same request to other backend servers. If sticky session is enabled and the load balancer receives no response from the backend server within the response timeout duration, the load balancer returns a 504 Gateway Timeout error to the client directly. The response timeout duration ranges from 1 to 300.
   Maximum New Connections per AZ	Specifies the maximum number of new connections that a listener can handle per second in each AZ. Unlimited is selected by default. You can select Limit request to set the maximum number of new connections. The value ranges from 1 to 1,000,000. If the value is greater than the number defined in the load balancer specifications, the latter is used as the limit. NOTE: This option is available in certain regions. You can see which regions support this option on the console.
   Maximum Concurrent Connections per AZ	Specifies the maximum number of concurrent connections that a listener can handle per second in each AZ. Unlimited is selected by default. You can select Limit request to set the maximum number of concurrent connections. The value ranges from 1 to 1,000,000. If the value is greater than the number defined in the load balancer specifications, the latter is used as the limit. Reducing the concurrent connection limit does not interrupt established connections. NOTE: This option is available in certain regions. You can see which regions support this option on the console.
   Tag	Adds tags to the listener. Each tag is a key-value pair, and the tag key is unique. NOTE: This option is available in certain regions. You can see which regions support this option on the console.
   Description	Provides supplementary information about the listener. You can enter a maximum of 255 characters.
   HTTP Headers	Select HTTP headers as needed. Transferring client information Rewrite X-Real-IP to transfer the client IP address. Rewrite X-Forwarded-For-Port to transfer the client port. Rewrite X-Forwarded-Host to transfer the client domain name. Transferring load balancer information Rewrite X-Forwarded-Proto to transfer the listener protocol. Rewrite X-Forwarded-ELB-IP to transfer the load balancer EIP. Rewrite X-Forwarded-Port to transfer the listener port. Rewrite X-Forwarded-ELB-ID to transfer the load balancer ID. For details, see HTTP Headers. NOTE: More HTTP headers are coming soon. See the available HTTP headers on the management console.

4. Click Next: Configure Request Routing Policy.
   1. You are advised to select an existing backend server group.
   2. You can also select Create new to create a backend server group.
      1. Configure the backend server group by referring to Table 3.
      2. Click Next: Add Backend Server. Add backend servers and configure a health check for the backend server group.

         For details about how to add backend servers, see Backend Server Overview. For the parameters required for configuring a health check, see Table 4.

5. Click Next: Confirm.
6. Confirm the configurations and click Submit.

Popular Questions