This topic describes the non-standard HTTP headers supported by Application Load Balancer (ALB) and how to add a non-standard HTTP header to a listener. You can customize the non-standard headers to implement features.
Non-standard HTTP headers supported by ALB
An HTTP header is a part of an HTTP request or response and carries additional information about the request or response. You can configure non-standard HTTP headers on a browser or a web server based on your business requirements. The following table describes the non-standard HTTP headers supported by ALB.
Header | Description | Listener protocol |
X-Forwarded-For | Listeners can use the Format:
For more information about how to enable ALB to preserve client IP addresses, see Enable ALB to preserve client IP addresses. |
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SLB-ID | Listeners can use the |
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X-Forwarded-Proto | Listeners can use the Format: |
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X-Forwarded-Port | Listeners can use the Format: |
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X-Forwarded-Clientcert-subjectdn | Listeners can use the To use this header, you must specify a name for the custom header. | HTTPS |
X-Forwarded-Clientcert-issuerdn | Listeners can use the To use this header, you must specify a name for the custom header. | HTTPS |
X-Forwarded-Clientcert-fingerprint | Listeners can use the To use this header, you must specify a name for the custom header. | HTTPS |
X-Forwarded-Clientcert-clientverify | Listeners can use the To use this header, you must specify a name for the custom header. | HTTPS |
X-Forwarded-Client-srcport | Listeners can use the Format: |
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Add HTTP headers in the console
Add an HTTP header when you create a listener
Log on to the ALB console.
In the top navigation bar, select the region in which the ALB instance is deployed.
Use one of the following methods to open the listener configuration wizard:
On the Instances page, find the ALB instance that you want to manage 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.
In the Configure Listener step, configure the following parameters and click Next.
Parameter
Description
Listener Protocol
Select a listener protocol.
Advanced Settings
You can click Modify to configure the advanced settings.
Custom HTTP Header
Select the HTTP headers that you want to add.
NoteFor more information about other parameters, see the following topics:
Complete the configurations as prompted.
Add an HTTP header to an existing listener
Log on to the ALB console.
In the top navigation bar, select the region in which the ALB instance is deployed.
On the Instances page, click the ID of the ALB instance that you want to manage.
Click the Listener tab, find the listener that you want to manage and choose
Modify Listener in the Actions column. In the Modify Listener dialog box, click Modify on the right side of Advanced Settings.
In the Custom HTTP Header section, add or remove HTTP headers and click Save.
Add HTTP headers by making API calls
You can specify the headers that you want to add when you call the API to create a listener. When you call the API to add, keep, or remove headers for an existing listener.
To add an HTTP header when you create a listener, set the XForwardedForConfig parameter when you call the CreateListener operation.
To manage the HTTP headers of an existing listener, modify the XForwardedForConfig parameter when you call the UpdateListenerAttribute operation.
References
Console operations
For more information about how to enable ALB to forward HTTP requests, see Add an HTTP listener.
For more information about how to enable ALB to forward HTTPS requests, see Add an HTTPS listener.
For more information about how to enable ALB to forward QUIC requests, see Add a QUIC listener.
API references
CreateListener: Creates an HTTP, HTTPS, or QUIC listener. You can set the XForwardedForConfig parameter in the request to add HTTP headers.
UpdateListenerAttribute: Modifies the configurations of a listener. You can modify the XForwardedForConfig parameter in the request to add, keep, or removes HTTP headers.