WLC MAC Filtering

Question

Hello
One thing I am confused is if I set MAC filtering on a WLC but do not populate with any MAC addresses will it block all MAC addresses or allow all?
Anyone can advise on this or please share information?
Thanks

Answer 1

When the database is empty then it will block all:
MAC Address Filter (MAC Authentication) on WLCs
When you create a MAC address filter on WLCs, users are granted or denied access to the WLAN network based on the MAC address of the client they use.
There are two types of MAC authentication that are supported on WLCs:
Local MAC authentication
MAC authentication using a RADIUS server
With local MAC authentication, user MAC addresses are stored in a database on the WLC. When a user tries to access the WLAN that is configured for MAC filtering, the client MAC address is validated against the local database on the WLC, and the client is granted access to the WLAN if the authentication is successful.
By default, the WLC local database supports up to 512 user entries.
The local user database is limited to a maximum of 2048 entries. The local database stores entries for these items:
Local management users, which includes lobby ambassadors
Local network users, which includes guest users
MAC filter entries
Exclusion list entries
Access point authorization list entries
Together, all of these types of users cannot exceed the configured database size.
In order to increase the local database, use this command from the CLI:
<Cisco Controller>config database size ?
<count> Enter the maximum number of entries (512-2048)
Alternatively, MAC address authentication can also be performed using a RADIUS server. The only difference is that the users MAC address database is stored in the RADIUS server instead of the WLC. When a user database is stored on a RADIUS server the WLC forwards the MAC address of the client to the RADIUS server for client validation. Then, the RADIUS server validates the MAC address based on the database it has. If the client authentication is successful, the client is granted access to the WLAN. Any RADIUS server which supports MAC address authentication can be used.