Dynamic Access Control Lists (ACL)

The user-based dynamic policy access control lists (ACL) feature uses the existing RADIUS Access-Accept and change of authorization (CoA) mechanism to override existing policy rules associated with a user by including a new vendor specific attribute (VSA) in the CoA and Access-Accept. When a CoA request or Access-Accept response to apply a particular set of match conditions and actions (or an action-set) is received, a look-up is performed to determine which policy profile the specified user was authenticated in, and the action-set ID specified in the CoA/Access-Accept is applied in that user‘s profile.

Note

You must configure VCAP partitioning to use dynamic ACL (see VCAP Partitioning).

If ACL style policy is not selected, or if the specified action-set does not exist, or if insufficient resources are available, the dynamic ACL rules are not applied and a NAK response to the RADIUS CoA request are returned. The maximum number of Dynamic ACL rules per user is 64. Access-Accept can include multiple adds using the += operation (this operation is not supported as part of RADIUS CoA request). Access-Accept usage does not support delete operation is ignored. Dynamic ACL rules can be deleted using an explicit CoA delete or are deleted when the dynamic session associated with the user is deleted.

Note

The maximum length of a RADIUS packet size is 4096 (both UDP and TLS), which can prevent the Dynamic ACLs from being sent to get trimmed via VSA 232 due to the lengthier ACL lists.

Dynamic ACLs and Layer 7 policy share the slices not used by TCI overwrite-enabled as one shared resource pool (see VCAP Partitioning). Dynamic ACLs have a higher priority to override Layer 7 policy (DNS) entry matches.

Beginning with Release 32.1, masking IPv4 addresses, L4 ports, and IP protocol numbers are supported. The mask is a required value and must be greater than zero and less than or equal to the maximum number of bits in the field being masked. For example, an IPv4 address mask value must be between 1 and 32.

To see an example of dynamic ACL VSA string, see Example Dynamic ACL VSA String.