Method and device of Portal centralized authentication

The invention discloses a method and a device of Portal centralized authentication. The method and the device of the Portal centralized authentication utilize a Fit AP flow-based transmitting module. When STA (single thread apartment) authentication is not passed, a private network internet protocol (IP) address is distributed to the un-authenticated STA and a centralized transmitting module is utilized in a default mode and data of all users are intensively transmitted to an AC (auto-coder) to be handled. Corresponding AC interfaces enable the Portal authentication to be handled according to normal Portal process. The AC issues a MAC (physical address) of the authenticated STA and issues instructs to the Fit AP to open a local forwarding function through a control and provisioning of wireless access points (CAPWAP) channel after the Portal authentication of the STA is passed, wherein the local forwarding function are contraposed to the STA. Meanwhile, the AC issues instruments to the Fit AP to break previous wireless connections and the STA starts a DHCP (dynamic host configuration protocol) requirement to obtain a public network IP address. The method and the device of the Portal centralized authentication can not only a solve AC centralized Portal authentication problem under the Fit AP local transmitting condition in existing wireless local area network (WLAN) but also can solve the problem of occupying the public network IP address before a Portal user is authenticated.