必须得用access接口，hybrid口不行

dhcp enable

interface Vlanif1
ip address 192.168.1.1 255.255.255.0
dhcp select interface

interface MEth0/0/1

interface GigabitEthernet0/0/1
port link-type access
port-isolate enable group 1

interface GigabitEthernet0/0/2
port link-type access
port-isolate enable group 1

interface GigabitEthernet0/0/2
port link-type access