The global association list serves the same purpose as an Association Access Control List (ACL). However, the Association ACL allows a limited number of entries, a few thousand only, and does not suffice the requirements of a large deployment. This gap is filled by a global association list, which is much larger (with tens of thousands of entries). Both lists co-exist in the system. When an access request comes in, the association ACL is looked up first and if the requesting MAC address is listed in one of the deny ACLs, the association is denied. But, if the requesting client is permitted access, or if in case none of the ACLs list the client‘s MAC address, the global association ACL is checked. Once authenticated, the client‘s credentials are cached on the Access Point, and subsequent requests are not referenced to the controller. An entry in an APs credential cache means a pass in the global association list.
global-association-list <GLOBAL-ASSOC-LIST-NAME>
global-association-list <GLOBAL-ASSOC-LIST-NAME>
| <GLOBAL-ASSOC-LIST-NAME> | Specify the global association list name. If a list with the same name does not exist, it is created. Map this global association list to a device (controller) or a controller profile. Once associated, the controller applies this association list to requests received from all adopted APs. For more information, see use (profile/device-config-mode-commands). The global association list can also be mapped to a WLAN. The usage of global access lists is controlled on a per-WLAN basis. For more information, see association-list. | 
nx9500-6C8809(config)#global-association-list my-clients
nx9500-6C8809(config-global-assoc-list-my-clients)#?
Global Association List Mode commands:
  default-action  Configure the default action when the client MAC does not
                  match any rule
  deny            Specify MAC addresses to be denied
  no              Negate a command or set its defaults
  permit          Specify MAC addresses to be permitted
  clrscr          Clears the display screen
  commit          Commit all changes made in this session
  do              Run commands from Exec mode
  end             End current mode and change to EXEC mode
  exit            End current mode and down to previous mode
  help            Description of the interactive help system
  revert          Revert changes
  service         Service Commands
  show            Show running system information
  write           Write running configuration to memory or terminal
nx9500-6C8809(config-global-assoc-list-my-clients)#
         nx9500-6C8809(config)#global-association-list vtt-list
nx9500-6C8809(config-global-assoc-list-vtt-list)#permit 01-22-33-44-55-66 description sample
nx9500-6C8809(config-global-assoc-list-vtt-list)#permit 40-B8-9A-39-F1-27 description acer
nx9500-6C8809(config-global-assoc-list-vtt-list)#permit 42-B8-9A-39-F1-27 description ami
nx9500-6C8809(config-global-assoc-list-vtt-list)#permit 6C-40-08-B2-80-6C description mac
nx9500-6C8809(config-global-assoc-list-vtt-list)#permit E0-98-61-34-11-47 description my_mobile
nx9500-6C8809(config-global-assoc-list-vtt-list)#show context global-association-list vtt-list default-action deny permit 01-22-33-44-55-66 description sample permit 40-B8-9A-39-F1-27 description acer permit 42-B8-9A-39-F1-27 description ami permit 6C-40-08-B2-80-6C description mac permit E0-98-61-34-11-47 description my_mobile nx9500-6C8809(config-global-assoc-list-vtt-list)#

Note
Ensure that the global association list is associated with the profile being applied on the access point.nx9500-6C8809(config-profile-testAP505)#use global-association-list server vtt-list
nx9500-6C8809(config-profile-testAP505)#show context include-factory | include global-association-list service global-association-list blacklist-interval 60 use global-association-list server vtt-list nx9500-6C8809(config-profile-testAP505)#
ap505-13403B(config-device-94-9B-2C-13-40-38)#use global-association-list server vtt-list
ap505-13403B(config-device-94-9B-2C-13-40-38)#show context include-factory | include global-association-list use global-association-list server vtt-list ap505-13403B(config-device-94-9B-2C-13-40-38)#
nx9500-6C8809(config-device-00-23-68-88-0D-A7)#use global-association-list server vtt-list
nx9500-6C8809(config-device-00-23-68-88-0D-A7)#show context include-factory | include global-association-list use global-association-list server vtt-list nx9500-6C8809(config-device-00-23-68-88-0D-A7)#
nx9500-6C8809(config-wlan-GLAssList)#association-list global vtt-list
nx9500-6C8809(config-wlan-GLAssList)#show context include-factory | include association-list association-list global vtt-list nx9500-6C8809(config-wlan-GLAssList)#