HTTP Headers

HTTP headers are a list of strings sent and received by both the client and server on every Hypertext Transfer Protocol (HTTP) request and response. This section describes HTTP headers supported by HTTP and HTTP listeners.

**Table 1** Transfer headers
Header	Feature	Description
X-Forwarded-ELB-IP	Transfer Load Balancer EIP	Transmits the EIP bound to the load balancer to backend servers through the X-Forwarded-ELB-IP header. The format is as follows (XX.XXX.XX.XXX indicates the EIP of the load balancer): X-Forwarded-ELB-IP: XX.XXX.XX.XXX
X-Forwarded-Port	Transfer Listener Port Number	Transmits the port number used by the listener to backend servers through the X-Forwarded-Port header.
X-Forwarded-For-Port	Transfer Port Number in the Request	Transmits the port number used by the client to backend servers through the X-Forwarded-For-Port header.

**Table 2** Rewrite headers
Header	Feature	Description
X-Forwarded-Host	Rewrite X-Forwarded-Host	Rewrites the client Host header into the X-Forwarded-Host header and transmits it to the backend servers. If this option is disabled, the X-Forwarded-Host header of the client will be transmitted to the backend servers.

Enabling HTTP/HTTPS Headers

Go to the load balancer list page.
You can enable these header features in either of the following ways:
- On the displayed page, locate the load balancer and click its name. On the Listeners tab, click Add Listener.
- On the displayed page, locate the load balancer and click Add Listener in the Operation column.
On the Add Listener page, expand Advanced Settings (Optional) and enable each header as needed.
Configure the listener as prompted.
Confirm the configuration and click Submit.

Modifying HTTP Headers

Go to the load balancer list page.
On the displayed page, locate the load balancer and click its name.
Click the Listeners tab, locate the target listener and click Edit in Operation column.
On the displayed page, expand Advanced Settings (Optional) and enable or disable each header.
Click OK.