How set to MAC Based ACL on GS724Tv4?

Hi Dongmin 

Welcome to Community!

For #1:

By default, there is one rule that to deny all;

So you only need add rule to permit the specific MAC address.

For #2:

In MAC Mask field:

An F means that the bit is not checked, and a zero in a bit position means that the data must equal the value given for that bit.

For example, if the MAC address is aa:bb:cc:dd:ee:ff, and the mask is 00:00:ff:ff:ff:ff, all MAC addresses with aa:bb:xx:xx:xx:xx result in a match (where x is any hexadecimal number). A MAC mask of 00:00:00:00:00:00 matches a single MAC address.

For detailed infor, please refer to UM document at here 

Hope it helps!

Regards,

Eric