1 Personal Information
Name: Ho Yi rain
Class: calculated 1813
Student ID: 201821121071
2 head to experiment
Familiar with Packet Tracer tool. Analysis caught application layer protocol packets, application layer protocol-depth understanding, including syntax, semantics, timing.
3 experimental content
Use Packet Tracer, properly configured network parameter, packet data capture and analysis application layer protocol, the protocol comprising DNS, FTP, DHCP, stmp, pop3. Steps include:
The establishment of network topology :
Network topology of this experiment are as follows, by the terminal and a PC connected to a server composition.
In which the PC IP address: 192.168.1.71
Server (Serve) end IP address is: 192.168.1.72
3.1 DNS
(1) Configuration Parameters
Client
IP Address: 192.168.1.71
DNS Server：192.168.1.72
Service-Terminal
IP Address: 192.168.1.72
DNS Server：192.168.1.72
Configure the server and the client
(2) capture and analyze packets captured
Grab DNS packets and analysis
0
Request packet and data analysis:
PC terminal sends a request to the server, requesting the yy.H (where YY is a second level domain, H is a domain name) of IP addresses, TTL of the packets recorded survival time was 86400, TYPE is a type of query, CLASS represents query class. DNS Query class represents a DNS request message.
The corresponding message and data analysis:
The server sends the appropriate message to the PC client, pointed out that the domain name into an IP address YY.H is 192.168.1.72, TTL represents the expiry time of the cache resource record, that is, the corresponding message expiration time is 86400.
3.2 FTP
(1) Configuration Parameters
Open the server-side server in the FTP, the user name HYY, password is also HYY.
(2) capture and data analysis
Click to open the desktop PC client in the Command Prompt, enter ftp 192.168.1.72 connected to the server, log on
Ftp 192.168.1.72 input response message, the client sends the request message to the server, the server transmits to the client PC side below shown in accordance with the request, wherein the statement: Message: Welcome to PT Ftp server, represents a successful connection, Code: 220 represents waiting for a user operation.
Enter the user name, the client sends a request to the server message, the user name is sent non-server, the server to the PC client returns a response message in the following figure, Username ok, need password indicated by the user name, and requests the user to enter a password 331 represents the current state.
After entering the password, the client sends a request message to the server password, the server returns the following response message, which statement Message: Logged in express password is correct, successful landing, you can perform the operation.
3.3 DHCP
(1) Configuration Parameters
Click on the server Services, DHCP, click on, it is turned on.
Open the PC will change the state of the Static DHCP.
(2) capture and data analysis
To fetch packets
3.4 smtp and pop3
(1) Configuration Parameter
The IP address of the PC client and the server is changed to 3.1 experiment with the corresponding IP address.
1. Server (Server0) parameters
Adding to the server side in three IP is 192.168.1.72
User1:Q Password:123
User2:W Password:123
2.PC end parameters
Open the PC end of the Configure Mail, fill in the user login information e-mail:
Your Name:Q
Email Address:[email protected]
Incoming Mail Server:YY2.H
Outgoing Mail Server:YY3.H
User Name:Q
Password:123
Click save login.
Edit the message, fill in the recipient's e-mail domain name, and click send to send.
Login recipients e-mail account to view the received messages.
(2) capture and data analysis
To fetch packets
data indicates that the message body
src-ip represents the load balancing when routing based on source IP address.
dst-ip indicates that the destination IP address basis.
pop3: reading the mail protocol
smtp: Send mail protocol