Interface-detection-based externally-connected protection device and method

An interface-detection-based externally-connected protection device, comprising internal interfaces (B1˜B3, D1, D2), external interfaces (A1˜A3, C1, C2), and a switch module (130), wherein:

• The internal interfaces are used for connecting to a protected device (200);
• The external interfaces are used for connecting to external devices that need to access the protected device;
• The external interfaces (A1˜A3, C1, C2) are connected with one-to-one correspondence to the internal interfaces (B1˜B3, D1, D2) by means of the switch module (130);
• At least two of the external interfaces are used for connecting to a predetermined type of data transmission external device;
• The type and quantity of the internal interfaces are compatible with the type and quantity of the external interfaces, wherein each internal interface is used in a to one connection with each external interface of the protected device;
• The externally-connected protection device further comprises a device type detection module (110) and an alarm module (140);
• The device type detection module (110) is used to detect the data transmission type of any external device connected to any external interface, send an alarm instruction to the alarm module (140) according to the detection result, and instruct the switch module to connect or disconnect the external interface with the corresponding internal interface;
• The alarm module (140) is used to perform alarm operations according to the received alarm instruction.