想问一下交换机端口同时配置 access 、 trunk端口 表示是什么意思,还有switchport trunk allowed vlan add 命令的含义?配置如下:interface GigabitEthernet2/28switchport access vlan 400switchport trunk allowed vlan 8,242,244,300switchport trunk allowed vlan add 302-304switchport mode trunkchan...