Chapter 2:Application layer ▣2.1 Principles of 2.6 P2P file sharing network applications 2.7 Socket programming 2.2 Web and HTTP with TCP 2.3 FTP 2.8 Socket programming ▣2.4 Electronic Mail with UDP ÷SMTP,POP3,IMAP 2.9 Building a Web ▣2.5DNS server 2:Application Layer 2 2: Application Layer 2 Chapter 2: Application layer  2.1 Principles of network applications  2.2 Web and HTTP  2.3 FTP  2.4 Electronic Mail ❖ SMTP, POP3, IMAP  2.5 DNS  2.6 P2P file sharing  2.7 Socket programming with TCP  2.8 Socket programming with UDP  2.9 Building a Web server