In the maintenance of rack system, a computing device may implement a plurality of smart plugs and a communication bus in a system. A smart plug may be plugged into a server node for communication between a management node and a designated server node. The communication bus may be coupled to the smart plugs for transmitting I2C packets. A server node may be associated with a corresponding smart plug that includes a unique address on the communication bus. The smart plug may be configured to receive a message via the communication bus. The smart plug is configured to determine whether the request is addressed to a unique address associated with the smart plug. Upon determining that the message is addressed to the unique address, the smart plug may reformat the request compatible with server node port using the local address. Reformatting request may depend on types of server node ports.