Each entry consists of a CIDR block and a description for the CIDR block. You can add, modify, or delete entries for a prefix list on the Prefix List Details page.

Prerequisites

If RAM users are used, the RAM users are granted permissions on prefix lists. For more information, see Grant RAM users permissions on prefix lists.
Note The prefix list feature is available only in some regions.

Add entries to a prefix list

On the Prefix List Details page, you can add an entry to a prefix list.

  1. Log on to the ECS console.
  2. In the left-side navigation pane, choose Network & Security > Prefix List.
  3. In the top navigation bar, select a region.
  4. On the Prefix List page, find the prefix list to which you want to add an entry and click the ID of the prefix list.
  5. On the Prefix List Details page, add an entry to the prefix list.
    1. On the Entries tab, click Add.
    2. Enter a CIDR block in the CIDR Block field and enter a description for the CIDR block in the Description field.
      The following limits apply to the 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 multiple CIDR blocks with a space or a comma (,).
      • The address type of a CIDR block in an entry is determined by the Address Family parameter. You cannot combine IPv4 and IPv6 CIDR blocks in a single prefix list.
      • CIDR blocks within entries in a prefix list must be unique. For example, you cannot specify two 192.168.1.0/24 CIDR blocks within the same 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 used, the system automatically converts it to the zero compression format.

        For example, if you specify 2001:0DB8:0000:0000:0000:0000:0000:0000/32, the system automatically converts it to 2001:db8::/32.

    3. Click Save in the Actions column.
    If you want to add multiple entries to the prefix list, repeat the preceding operations.

Modify entries in a prefix list

On the Prefix List Details page, you can modify entries in a prefix list.

  1. In the left-side navigation pane, choose Network & Security > Prefix List.
  2. In the top navigation bar, select a region.
  3. On the Prefix List page, find the prefix list in which you want to modify entries and click the ID of the prefix list.
  4. On the Prefix List Details page, find the entry that you want to modify and click Modify in the Actions column.
  5. Modify the CIDR block and its description.
    The following limits apply to entries in a prefix list:
    • You can enter multiple CIDR blocks at a time. Separate multiple CIDR blocks with a space or a comma (,).
    • The address type of a CIDR block in an entry is determined by the Address Family parameter. You cannot combine IPv4 and IPv6 CIDR blocks in a single prefix list.
    • CIDR blocks within entries in a prefix list must be unique. For example, you cannot specify two 192.168.1.0/24 CIDR blocks within the same 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 used, the system automatically converts it to the zero compression format.

      For example, if you specify 2001:0DB8:0000:0000:0000:0000:0000:0000/32, the system automatically converts it to 2001:db8::/32.

  6. Click Save in the Actions column.

Delete entries from a prefix list

On the Prefix List page, you can delete entries from a prefix list.

  1. In the left-side navigation pane, choose Network & Security > Prefix List.
  2. In the top navigation bar, select a region.
  3. On the Prefix List page, find the prefix list from which you want to delete entries and click the ID of the prefix list.
  4. On the Prefix List Details page, use one of the following methods to delete entries:
    • Delete a single entry: Find the entry that you want to delete and click Delete in the Actions column.
    • Delete multiple entries: Select the entries that you want to delete and click Delete in the lower part of the page.