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Web Servers. Web server software is a product that works with the operating system The server computer can run more than one software product such as e-mail and FTP With both a LAN and the Web, controlling access is very important The Web server can be part of the LAN
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Web Servers • Web server software is a product that works with the operating system • The server computer can run more than one software product such as e-mail and FTP • With both a LAN and the Web, controlling access is very important • The Web server can be part of the LAN • Web communication and LAN communication are different
Web Server Platforms-Microsoft • Windows NT (IIS 4) • IIS (Internet Information Server) was added in the mid-1990s, and support for ASP was added later • Windows 2000 (IIS 5) • IIS part of the OS from the beginning • .NET Framework add-on allows use of ASP.NET • Windows Server 2003 (IIS 6) • .NET Framework integrated into OS
Other Microsoft Server Products • Application Center • Allows you to manage a cluster of servers as if it is one server • Biztalk Server • Connects to your business partners using XML • Commerce Server • Builds e-commerce sites in a short amount of time
Other Microsoft Server Products • Internet Security and Acceleration Server • Combines a firewall product with a Web cache • Operations Manager • Helps decrease support costs for a server environment • SharePoint Portal Server • Set up a site that is highly personalized
Configuring TCP/IP in Windows • To determine TCP/IP configuration, type ipconfig at a command prompt
How a Web Server Works • HTTP (Hypertext Transfer Protocol) defines how information is passed between a browser and a Web server • The two most popular Web servers are • Apache from Apache Software Foundation • Internet Information Services (IIS) from Microsoft • The original Web server from Microsoft available on Windows NT was Internet Information Server • Almost two-thirds of all Web servers use Apache
How a Web Server Works • As is true with other servers such as DNS, Web servers listen for communication at a port • The default port is 80 • You can also create Web servers at port numbers greater than 1023 • Each Web server has a root, which is where you store the HTML documents
Understanding HTTP • The current version of HTTP is 1.1 • Virtually no browsers are so old that they do not support 1.1 • HTTP is a stateless protocol, meaning that each Web page sent is independent of every other Web page sent • This makes it more challenging to create a shopping cart application
Understanding HTTP • HTTP 1.1 supports persistent connections • This allows the browser to receive multiple files in one TCP connection • This can speed up communication • Although you see a single page in your browser, it can be composed of many text and image files
Understanding HTTP • When the browser sends a request to a Web server, it looks like: GET /hello.htm HTTP/1.1 Host: www.technowidgets.com • The above requests the hello.htm file from the root of the Web server • It specifies the host of www.technowidgets.com • There could be multiple hosts at the IP address
Understanding HTTP • The following shows some of the headers along with the HTML that the Web server would send: HTTP/1.1 200 OK Server: Microsoft-IIS/5.0 Content-Type: text/html Last-Modified: Fri, 17 May 2005 18:21:25 GMT Content-Length: 43 <html><body> Hello, World </body></html> • The headers contain information about the page
Features in Apache • Apache 1.3 was used for many years but version 2.0 was released in 2001 • Apache can also be used as a proxy server • A proxy server isolates your real Web server from the Internet • Apache 2.0 has • Better support for Windows • Support for IPv6 • Simplified configuration • Unicode support in Windows • Multilanguage error responses • Apache supports many programming languages such as Perl and PHP
Features in IIS • IIS versions associated with Windows versions • Windows NT – IIS 4.0 • Windows 2000 – IIS 5.0 • Windows Server 2003 – IIS 6.0 • SMTP can be easily added so you can send e-mail from your Web pages
Features in IIS 5.0 • Web Distributed Authoring and Versioning (WebDAV) • Allows a server to share Web-based files • Named virtual hosting • Multiple Web sites can share a single IP address • Per Web site bandwidth throttling • Control bandwidth by Web site • Kerberos authentication • Secure Sockets Layer 3.0 • Encrypted communication
Features in IIS 6.0 • Increased security • Default permits only HTML documents • Expanded language support • Can use XML and SOAP • Support for IPv6 • Increased dependability • Kernel-mode HTTP service • Self-healing mechanism
Components in IIS • File Transfer Protocol (FTP) server • To transfer files between user and server • FrontPage 2000 Server Extensions • Used by programs to transfer files to and from a Web site • NNTP Service • Used to create user forums • SMTP Service • World Wide Web Server
File System Permissions • Permission allow you to control access to the resources on a computer such as a Web page, a document, or a program • In Windows, the NTFS file system is required in order to assign permissions • All Linux file systems incorporate permissions
Hosting Multiple Web Sitesby Port Number • Associate each new Web site with a port above 1023 • To retrieve a Web page from a site at port 8080 • www.technowidgets.com:8080/prod.htm • Because it requires a user to add the port number, it is not a popular method
UNIX/Linux • UNIX was introduced in 1969 • Linux is from the early 1990s • Based on MINIX • Three basic components • Kernel – central portion of OS • File system – provides input and output mechanisms • Shell – provides user interface
Linux • Source code is freely available • Developers can make changes • Available from a number of organizations • Red Hat • Mandrake • SuSe
Summary • Server administration focuses on LANs • Web server administration focuses on the Internet • Both types of administrators install, configure, and maintain servers • Many pieces make up the network • There are many Web server platforms from which to choose
Summary • Web servers use HTTP to send HTML documents • IIS is from Microsoft while Apache is from Apache Software Foundation • IIS modifications are made through property pages • Apache modifications are typically made by changing /etc/httpd/conf/httpd.conf