Although the design of IPMC as the core of server management is becoming more and more mature, IPMC is still designed in the form of "integration" directly welded on the server motherboard, which has a high complexity in hardware update and maintenance. In this context, this paper puts forward the idea of "hardware plug-in", which makes IPMC into a pluggable board in the form of golden finger hardware interface. This board can not only solve the problems mentioned above, but also has Gigabit Ethernet switching function. The board hardware is mainly composed of microcontroller MSP432E401Y and L2 Ethernet switch chip KSZ9897R. In order to solve the hardware redundancy problem of Ethernet communication between boards, this design uses a transformerless Ethernet circuit interconnection. After the simulation and optimization of via parameters by HFSS software and the eye diagram and S-parameter test of high-speed signals between boards, the results show that the plug-in board hardware designed in this paper has a maximum voltage loss of 3.5dB when transmitting gigabit rate signals. The return loss is greater than 10dB, which fully meets the loss requirements of the IEEE802.3 standard for Ethernet signals.