摘要 本畢業論文（設計）是在Visual Basic 6.0編程環境下實現的，主要研究如何使用交換機和利用VB程序設計語言來開發一套圖形界面的校園網交換機節點管理程序，對交換機各端口進行設置，修改某一子網在指定時間內的連通狀態。完成此管理程序能夠方便的管理校園網的交換機節點，減少管理員定時開通或關閉子網的工作量。該程序使用VB自帶的Winsock控件telnet到交換機的某一端口，然后通過對交換機發送一系列命令，來設置交換機各Vlan和端口的相關狀態；將交換機各子網的相關信息、修改子網連通狀態的時間信息等存儲在文本文件中，使用一個timer控件定時訪問這些文本文件來決定是否修改某子網的連通狀態，然后使用訪問控制列表（Access Control List, ACL）來修改。通過完成這個題目，加深對交換機的理解，并且更好地學習編程思想，掌握VB語言的應用，了解軟件開發的過程，為以后進一步的研究打好基礎。
關鍵詞 VB，交換機，Winsock控件
Port Subnet Administrator
Abstract: Accomplished in Visual Basic 6.0 programming environment, this graduation thesis mainly studies how to make use of the switch and employ VB Programming Language to develop an administration program of a series of graphical interfaces campus web switch modes, setting up the switch ports and modifying the state of connection of some subnet in a certain time. The program can conveniently control campus web switch nodes so as to decrease the administrator’s work load that he turns on or off the subnet timely. Using Winsock control in VB, the program telnet the some port in switch. Then, by sending a series of orders to the switch, it puts up the state of connection of switch VLAN and ports. When the information relative to the switch subnets and the time information about modifying the state of connection of subnets are stored in the text files, the program using a timer control to open these files timely in order to decide whether it is revised the state of connection of some subnet or not, and then it is employed ACL to revise it. By finishing this paper, I get deeper understanding about the switch, learn more about the programming thought, grasp the application of VB Programming Language and know the process of developing software. All of these aspects lay the good foundations of my further research in future.
Keywords：VB，Switch，Winsock control
