Configuring Header Field Forwarding to Disable Response Packet Compression

Application Scenarios

The client usually declares that response compression is supported in the Accept-Encoding header, for example, Accept-Encoding: gzip. After the response passes through WAF, WAF considers that the response meets the compression standard and compresses the response. However, after receiving the response, the client cannot automatically decompress the response packet. The website then responds abnormally.

To address this issue, you can configure Forward Field to rewrite the Accept-Encoding header for the domain name on the WAF console so that WAF does not compress the response.

Resource and Cost Planning

Limitations and Constraints

Header field forwarding can be configured only in cloud CNAME access mode and dedicated mode.

Step 1: Buy the Professional Edition Cloud WAF

The following describes how to buy the standard edition cloud WAF.

1. Log in to the WAF console.
2. In the upper right corner of the page, click Buy WAF. On the purchase page displayed, select Cloud Mode for WAF Mode.
   • Region: Select the region nearest to your services that WAF will protect.
   • Edition: Select Professional.
   • Expansion Package and Required Duration: Set them based on site requirements.

3. Confirm the product details and click Buy Now in the lower right corner of the page.
4. Check the order details and read the WAF Disclaimer. Then, select the box and click Pay Now.
5. On the payment page, select a payment method and pay for your order.

   After the order is paid, click Access Console to go to the Dashboard page. Hover over the Product Details area to view the edition of the purchased instance and its specifications.

Step 2: Add Website Information to WAF

The following example shows how to add a website to WAF in cloud CNAME access mode.

• For details about the cloud load balancer access mode, see Connecting a Website to WAF (Cloud Mode - ELB Access).
• For details about the dedicated mode, see Connecting a Website to WAF (Dedicated Mode).

1. In the navigation pane on the left, choose Website Settings.
2. In the upper left corner of the website list, click Add Website.
3. Select Cloud - CNAME and click Configure Now.
4. Configure website information as prompted.
   Figure 1 Configuring basic information
   

   Table 2 Key parameters

   Parameter	Description	Example Value
   Domain Name	Domain name you want to add to WAF for protection. The domain name has an ICP license. You can enter a single domain name (for example, top-level domain name example.com or level-2 domain name www.example.com) or a wildcard domain name (*.example.com).	www.example.com
   Protected Port	The port over which the website traffic goes	Standard ports
   Server Configuration	Web server address settings. You need to configure the client protocol, server protocol, server weights, server address, and server port. Client Protocol: protocol used by a client to access a server. The options are HTTP and HTTPS. Server Protocol: protocol used by WAF to forward client requests. The options are HTTP and HTTPS. Server Address: public IP address (generally corresponding to the A record of the domain name configured on the DNS) or domain name (generally corresponding to the CNAME record of the domain name configured on the DNS) of the web server that a client accesses. Server Port: service port over which the WAF instance forwards client requests to the origin server. Weight: Requests are distributed across backend origin servers based on the load balancing algorithm you select and the weight you assign to each server.	Client Protocol: Select HTTP. Server Protocol: HTTP Server Address: IPv4 XXX.XXX.1.1 Server Port: 80
   Use Layer-7 Proxy	You need to configure whether you deploy layer-7 proxies in front of WAF. Set this parameter based on your website deployment.	Yes

5. Click Next and complete the basic information about the website to be protected. Perform the following operations as prompted on the Add Website page:
   Figure 2 Domain name added to WAF
   
   1. Whitelist back-to-source IP addresses.
   2. Test WAF.

   After the preceding steps are complete, you can check the Access Status of the added domain name in the domain name list. The Access Status of the domain name is Inaccessible at first. You need to modify the DNS record.

Step 3: Configure Header Field Forwarding

1. Log in to the WAF console.
2. In the navigation pane on the left, choose Website Settings.
3. In the Domain Name column, click the website domain name to go to the basic information page.
4. In the Forward Field column, click Modify. In the displayed Forward Field dialog box, enter a key/value pair, and click Add.

   Set Key to Accept-Encoding and Value to identity.

   Figure 3 Forward Field
   

5. Click OK.