The maximum number (N) of MAC address to be
secured on the port. The first N MAC addresses
learned or configured are made secured. If the
user wants to make the port secured for more than
one MAC address, the portSecurityExtTable is used
in addition to portSecuritySecureSrcAddr. If
changing the maximum number N of Mac address to M,
which is smaller than N, some MAC addresses are
removed. Setting this value to 1,
the portSecurityExtTable will not be used for this
port and the corresponding entries for this port
will also be removed from portSecurityExtTable.