An IP address blacklist or whitelist filters user requests, and blocks or allows requests from specific IP addresses. The IP list feature can restrict access sources and protect points of presence (POPs) from IP theft and attacks.
Usage notes
By default, the IP list feature is disabled. The IP blacklist and whitelist are mutually exclusive. You can configure only one of the lists.
You can add up to about 700 IPv6 addresses and up to 2,000 IPv4 addresses to a list. If you want to block more IP addresses, enable Dynamic Content Delivery Network (DCDN) security features. Security features are designed to block a large number of IP addresses. For more information, see Activate DCDN.
If an IP address is added to the blacklist, requests from the IP address can reach POPs but are rejected by the POPs, the HTTP 403 status code is returned, and requests from the IP address are recorded in the logs of Alibaba Cloud CDN.
The IP address blacklist and whitelist identify IP addresses based on Layer 7 HTTP IP recognition techniques. You are charged for network traffic that is generated when POPs block malicious requests. If clients access POPs over HTTPS, you are also charged for HTTPS requests.
IP address verification modes
When a client connects to a POP, the client IP address and the IP address that is used by the client to connect to the POP are determined based on whether a proxy is used. For example, the client IP address is 10.10.10.10, and the proxy IP address is 192.168.0.1.
If no proxy is used when a client connects to a POP, the following rules apply:
The value of the X-Forwarded-For (XFF) header in the user request is
10.10.10.10.The client IP address
10.10.10.10is the IP address that is used by the client to connect to the POP.
If a proxy is used when a client connects to a POP, the following rules apply:
The value of the XFF header in the user request is
10.10.10.10,192.168.0.1.The client IP address
10.10.10.10is the first IP address in the XFF header.The IP address that is used by the client to connect to a POP is the IP address of the proxy, which is
192.168.0.1.The client IP address is not the IP address that is used by the client to connect to the POP.
The IP list feature of Alibaba Cloud CDN supports three IP address verification modes. The following table describes the verification modes.
IP address verification mode | Description |
Determine based on the XFF header | This is the default mode. This mode verifies only the client IP address. The client IP address is the first IP address in the XFF header in a client request. If a proxy is used when a client connects to a POP, the client uses the IP address of the proxy to connect to the POP. In this case, access control in this verification mode may not be accurate. |
Determine based on the IP address that is used to connect to the POP | This mode verifies only the IP address that is used by a client to connect to a POP. |
Determine based on the XFF header and the IP address that is used to connect to the POP | This mode verifies the following IP addresses:
|
Procedure
Log on to the Alibaba Cloud CDN console.
In the left-side navigation pane, click Domain Names.
On the Domain Names page, find the domain name that you want to manage and click Manage in the Actions column.
In the left-side navigation tree of the domain name, click Access Control.
Click the IP Blacklist or Whitelist tab.
In the IP Blacklist or Whitelist section, click Modify.
Select Blacklist or Whitelist based on your business requirements.
Parameter
Description
Type
The following types of IP lists are supported:
Blacklist
Requests from IP addresses on the blacklist are blocked.
Whitelist
Only requests from IP addresses on the whitelist can access resources on the POPs.
Rules
Enter CIDR blocks, such as
192.168.0.0/24, or IP addresses, such as192.168.0.1. Make sure that no duplicate CIDR blocks exist. IPv4 and IPv6 addresses are supported. Separate multiple IP addresses with carriage return characters.IPv6: You can add up to about 700 IPv6 addresses to the list. The blacklist and whitelist support IPv6 addresses. The letters in IPv6 addresses are not case-sensitive. Examples:
FC00:AA3:0:23:3:300:300A:1234andfc00:0aa3:0000:0023:0003:0300:300a:1234. The notation of an IPv6 address must not be shortened. For example,FC00:0AA3::0023:0003:0300:300A:1234is invalid. CIDR blocks are supported. Example:FC00:0AA3:0000:0000:0000:0000:0000:0000/48.IPv4: You can add up to about 2,000 IPv4 addresses to the list.
The total length of the string that specifies IP addresses cannot exceed 30 KB in size.
NoteYou cannot use
0.0.0.0/0to specify all IP addresses.To specify all IPv4 addresses, use the following subnets:
0.0.0.0/1128.0.0.0/1
To specify all IPv6 addresses, use the following subnets:
0000:0000:0000:0000:0000:0000:0000:0000/18000:0000:0000:0000:0000:0000:0000:0000/1
IP Rules
You can select one of the following rules:
Determine based on the XFF header
Determine based on the IP address that is used to connect to the POP
Determine based on the XFF header and the IP address that is used to connect to the POP.
If the XFF header does not include an IP address, determine based on the IP address that is used to connect to the POP.
Rule Condition
Rule conditions can identify parameters in a request to determine whether a configuration takes effect on the request.
Do not use conditions
Select the configured rule conditions in Rules Engine. For more information, see Rules engine.
Click OK.
Sample configurations
Whitelist
Rules:
192.168.2.0/24Expected result: Only IP addresses that range from
192.168.2.1to192.168.2.254can access the resources of the specified domain name.Blacklist
Rules:
192.168.0.1Expected result: The IP address
192.168.0.1is not allowed to access the resources of the specified domain name.
FAQ
Related API operations
BatchSetCdnDomainConfig: configures an IP address blacklist or whitelist for multiple domain names at the same time. The ip_black_list_set parameter specifies an IP address blacklist and the ip_allow_list_set parameter specifies an IP whitelist.