Configuring Prefix Lists

BloxOne supports prefix lists that you configure to allow or deny access to network addresses that start with the prefixes you define in the prefix lists. A prefix is the far left bit of the far left octet of an IP address. You can use prefix lists in route maps and route filtering operations or use them as an alternative to access lists in BGP route filtering commands. A prefix list allows you to filter networks based on their subnet mask.

On the Prefix Lists page, the Cloud Services Portal displays the following information for each prefix list:

• The name of the prefix list.
• Whether the prefix list is Enabled or Disabled.

Click the down arrow to view the following details of a chosen prefix list:

• Action: The configured action for the prefix rule. This can be PERMIT or DENY.
  PERMIT allows access to the network addresses that start with the prefix, and DENY restricts access to the addresses.
• Prefix: The prefix of the IP addresses you defined for this routing rule.
• Prefix Length GE: The matching prefix length that is greater than or equal to the number you entered here.
• Prefix Length LE: The matching prefix length that is less than or equal to the number you entered here.
• Sequence: The number that defines the priority of the rule in the prefix list. The lower the number, the higher the priority.

You can also perform the following on the Prefix Lists page:

• Click  ... > Edit or select the check box for the respective prefix list and click the Edit button to modify the list.

• Select the respective prefix list and click Remove to delete a list.

• Enter the value that you want to search in the Search text box. The application displays the list of prefix lists that match the keyword in the text box.
• Click  to add filtering rules. You can save filtering rules for future use by clicking . Once a filter is saved, you can click to locate it for future use.
  

You can perform the following actions: