1. Web Server Technologies Part I: HTTP & Getting Started Joe Lima Director of Product Development Port80 Software, Inc. [email_address]

3. Preliminaries - Recommended Texts Administrating Web Servers, Security & Maintenance Larson and Stephens, Prentice Hall HTTP The Definitive Guide Gourley and Totty, et al., O’Reilly Online resources are plentiful and will be cited along the way. Web Server Technologies | Part I: HTTP & Getting Started

6. A Brief Digression on TCP/IP Web Server Technologies | Part I: HTTP & Getting Started HTTP sits atop the TCP/IP Protocol Stack Network Interfaces HTTP TCP IP Application Layer Transport Layer Network Layer Data Link Layer

9. A Brief Digression on TCP/IP, cont. Web Server Technologies | Part I: HTTP & Getting Started How an HTTP Message is delivered over TCP/IP connection: GET /index.html HTTP/1.1<CRLF> Host: www.hostname.com Con… HTTP Message’s data stream is chopped up into chunks small enough to fit in a TCP segment The segments are shipped to the right destination inside IP datagrams The chunks ride inside TCP segments used to reassemble them correctly on the other end of the connection

10. A Brief Digression on TCP/IP, cont. Web Server Technologies | Part I: HTTP & Getting Started HTTPS (HTTP + SSL/TLS) Although a different protocol, service and port, HTTPS is usually integrated with the Web server FTP Often run on the same box as the HTTP server to provide file transfer capabilities SMTP Sometimes run with Web server (email gateways) SSH Widely used instead of telnet for remote admin Other application layer protocols use TCP/IP to provide Internet services often found in company with HTTP

15. Basic HTTP Request/Response Cycle Web Server Technologies | Part I: HTTP & Getting Started HTTP Server HTTP Client Resource HTTP Request HTTP Response www.foo.com /bar Asks for resource by its URL: http://www.foo.com/bar.html

16. An HTTP Request/Response Chain Web Server Technologies | Part I: HTTP & Getting Started HTTP Client DMZ Local DNS External DNS Servers Internet Transparent Proxies HTTP Server Reverse Proxy LAN Egress Proxy Network at Hosting Provider Root DNS Servers