CNet: A Top-down Approach LAB

My solution of ComputerNetworking: A Top-down Approach Labs and Problems.

The Lectures of CNet please check:

講義のノートはこちらに取ります：

CNet Lectures

Lab	Solution	問題文の日本語翻訳
WiresharkLAB 0	-	-
Socket Prog1	A1	TCP/UDP Socket
LAB 1: WebServer	L1	ウェブサーバ
LAB 2: UDPPinger	L2	UDP Pinger
LAB 3: SMTP	L3	メールサーバ

Notes

WiresharkLAB0

Actually, this lab is from CS144.

DEMO: Wireshark

Wireshark is an application that lets you actually observe the datagrams being sent and received on your machine over the Internet.

We filtered for packets with a particular IP address (given by Keith):

Image: screenshot of Wireshark filter box, with ip.dst == 171.64.65.14 filter applied. This filters for IP packets with destination IP address 171.64.65.14.

We then pinged that IP address from a terminal window

$ ping 171.64.65.14

APPENDIX:Wireshark

A Network Packet Analyzer

You could filter the particular IP dst to examine its packet info.

Socket Programming: Creating Network Applications

• Implementation: Conform Protocol Standard
• Proprietary APP: Choose Port

127.0.0.1 is local hostname.

Socket Programming with UDP

Unreliable; Datagram

Socket Programming with TCP

Coneection-oriented; Reliable

Lab 1: WebServer

Based on TCP Protocol

Modular: Socket, Sys

Function:

• socket.socket(socket.AF_INET, socket.SOCK_STREAM): Initialization

• socket.bind((serverAdress, serverPort)): Bind socket (Usually Used For Server)

• socket.recv(buffer size): Receive obj

• socket.recvfrom(buffersize, (serverAddress, serverPort)): Receive obj from server