After you create an access list, you must reference the access list to
make it work. Access lists can be applied on either outbound or inbound
interfaces. This section describes guidelines on how to accomplish this task
for both terminal lines and network interfaces.
For inbound access lists, after receiving a packet, Cisco IOS XR
software checks the source MAC address of the packet against the access list.
If the access list permits the address, the software continues to process the
packet. If the access list rejects the address, the software discards the
packet.
For outbound access lists, after receiving and routing a packet to a
controlled interface, the software checks the source MAC address of the packet
against the access list. If the access list permits the address, the software
sends the packet. If the access list rejects the address, the software discards
the packet.

Note
|
An empty access-list (containing no access control elements) cannot
be applied on an interface.
|