陕西师范大学_软件工程-郭浩东DHCP详解.pdf

陕西师范大学 计算机网络 实验报告 年级： 2014 级 姓名： 郭浩东 学号： 实验名称：利用 wireshark 分析 DHCP 一、实验目的 加深对DHCP 协议进行全面的了解和认识 二、实验器材 Wireshark 三、 实验内容 1. Are DHCP messages sent over UDP or TCP? DHCP messages are sent over UDP (User Datagram Protocol). 2. Draw a timing datagram illustrating the sequence of the first four-packet Discover/Offer/Request/ACK DHCP exchange between the client and server. For each packet, indicated the source and destination port numbers. Are the port numbers the same as in the example given in this lab assignment? The port numbers are the same as the example in the Lab. 3.What is the link-layer (e.g., Ethernet) address of your host? The Link Layer address of my workstation is: 00:90:4b:69:dd:34 4. What values in the DHCP discover message differentiate this message from the DHCP request message? The values which differentiate the Discover message from the Request message are in “Option 53: DHCP Message Type”. 5. What is the value of the Transaction-ID in each of the first four (Discover/Offer/Request/ACK) DHCP messages? What are the values of the Transaction-ID in the second set (Request/ACK) set of DHCP messages? What is the purpose of the Transaction-ID field? The value of the Transaction ID is 0xe6746a7d. The second Transaction ID is 0xe4eff25f. A Transaction ID is used so that the DHCP server can differentiate between client requests during the request process. 6. A host uses DHCP to obtain an IP address, among other things. But a host’s IP address is not confirmed until the end of the four-message exchange! If the IP address is not set until the end of the four-message exchange, then what values are used in the IP datagrams in the four-message exchange? For each of the four DHCP messages (Discover/Offer/Request/ACK DHCP), indicate the source and destination IP addresses that are carried in the en