address substitution meaning in English

地址代换
地址替换

However , the user has to get the address via dhcp . so to realize certification at the application layer , the only way a user can leverage to get the address will be broadcasting . then there is inevitably the problem of address substitution or the availability of public network address as soon as the user turns on the machine
Vlan + web方式本身数据的传输是透明传输，但由于本身用户是通过dhcp得到地址，为了能够进行应用层的认证，用户必须通过广播得到地址，因此必然存在地址替换或用户开机就得到公网地址的问题。