Abstract: The campus network topology of the existing problems was analyzed, and according to a large flat layer 2 network design ideas, a device for the network core BARS wired and wireless integrated network topology was proposed. The topology can maximize the protection of existing investments, simply increasing the core layer BRAS device, and all of the original switches can be linked to the BRAS as a layer 2 device. BRAS equipment performance and characteristics were used to finish tunnel network users inside and outside the establishment, isolation, flow control, fault location and other fine management; large two-story structure features were used to achieve net IPv4/IPv6 dual and multicast services, various brands the unified management of wired and wireless devices. The topology used in the actual network environment BRAS equipment must be hot standby, wireless AC needs to support local forwarding.