(A series of test plans were carried out before implementation. The whole plan was explained step by step in great detail, including: 1. Laboratory simulation environment equipment and requirements 1. Experimental equipment 2. Test topology 3. IP address design 4. Configuration Requirements 5. Test requirements 2. Configuration scheme 1. Configuration of 3550-1 2. Configuration of 3550-2 3. Configuration of 3550-3. . . . 3. Test. . .)