A prefix list entry consists of a CIDR block and a description. You can add, modify, or delete prefix list entries based on your business requirements. This topic describes how to manage prefix list entries in the Elastic Compute Service (ECS) console.
If you use a Resource Access Management (RAM) user, the RAM user is granted permissions on prefix lists. For more information, see Control access to ECS resources by using RAM users.
Limits
The following limits apply to entries in a prefix list:
The total number of entries cannot exceed the value set for Max Entries.
You can enter multiple CIDR blocks at a time. Separate the CIDR blocks with spaces or commas (,).
The address type of a CIDR block in each entry is determined by the Address Family parameter. You cannot combine IPv4 and IPv6 CIDR blocks in a single prefix list.
CIDR blocks in entries in a prefix list must be unique. For example, you cannot specify 192.168.1.0/24 twice in the entries of the prefix list.
You can specify an IP address. The system automatically converts the IP address to a CIDR block.
For example, if you specify 192.168.1.100, the system automatically converts the IP address to 192.168.1.100/32.
If an IPv6 CIDR block is specified, the system automatically converts the IPv6 CIDR block to the zero compression format.
For example, if you specify 2001:0DB8:0000:0000:0000:0000:0000:0000/32, the system converts it to 2001:db8::/32.
Procedure
You can add, modify, or delete entries for a prefix list on the Prefix List Details page.
Log on to the ECS console.
In the left-side navigation pane, choose Network & Security >
> Prefix Lists. In the top navigation bar, select the region and resource group to which the resource belongs.
On the Prefix List page, find the prefix list that you want to manage and click the ID of the prefix list.
On the Prefix List Details page, manage the entries in the prefix list.
Add entries to the prefix list
On the Entries tab, click Add.
Enter a CIDR block in the CIDR Block field, enter a description for the CIDR block in the Description field, and then click Save.
If you want to add multiple entries to the prefix list, repeat the preceding steps.
Modify entries in the prefix list
On the Prefix List Details page, find the entry that you want to modify and click Modify in the Actions column.
Modify the CIDR block and the description and then click Save.
Delete entries from the prefix list
To delete a single entry, find the entry and click Delete in the Actions column.
To delete multiple entries, select the entries and click Delete in the lower part of the Entries tab.
References
You can call an API operation to manage prefix list entries and modify the name and description of a specific prefix list. For more information, see ModifyPrefixList.
After the modification, you may need to reference the prefix list. For information about how to reference a prefix list in a security group rule, see Add a security group rule.
For information about how to configure prefix lists, see Use prefix lists to simplify management of security group rules.