Building Your Own Internet Site
Connecting to the Net requires that we deal with issues related to physical and logical connectivity. The physical connectivity issues are based on the selection and provisioning of telco (telephone company) or cable lines. The options for physical connectivity with modest bandwidth appear to be ISDN (Integrated Services Digital Network), DSL (Digital Subscriber Line) and cable IP services.
The services I need to connect to the Internet fall into two categories: telco services and IP access provider. I really don't need ISP (Internet Service Provider) services, because I will be my own ISP. All the services an ISP usually provides are available on the system as I have it configured.
Of the technologies available, ISDN is the oldest, dating back to 1978. DSL and cable modems are relatively new technologies and availability is limited for all these technologies. (See “The (not so) Wonderful World of High-Speed Internet Access” by Jason Schumaker in this issue.) Since DSL and cable IP are not available in my area, connectivity will be provided by an ISDN line. Internet access is provided by US West and can be connected 24x7 (24 hours a day, 7 days a week) with “on demand” service. In the interest of keeping the initial cost of the site down, I have arranged to obtain a used 3Com Impact IQ ISDN network adapter (they really aren't modems) to attach my system to my selected IP access provider.
On the logical side of connectivity, we need routing support and an Internet address. In this case, the US West Network will provide routing and DNS (Domain Name Services) support to my site. To be addressable, I need an IP number for my site. Eight static IP numbers are being rented from US West for $15.00 US per month. This yields five usable IP addresses, with the remainder used for configuration purposes. (See “Simplified IP Addressing” by Gene E. Hector, LJ, January 2000.)
This configuration has been successfully tested from the Net. I connected the system, noted its dynamic address, then logged in to the system with HTTP, TELNET and FTP sessions from a remote location. This assures me the system configuration is ready to support the services I plan to use for this Internet site.
To be visible to users of the Internet, the site will need to have a domain name that is registered with an organization called Internic. The web page at http://www.internic.net/ has the information and forms to register a domain name. In order to register for a domain, you must have a primary and a secondary DNS with which you define your system. The people who are responsible for those systems should be aware of your intentions, or you may find your site falling off the Net.
A domain name is required to be visible as something other than its assigned IP number. It would be difficult to remember network addresses in the IP number format of ###.###.###.### (e.g., 192.168.1.1), so a domain name puts our site in the form of “mySite.com”. The Internet Access Provider will have to provide DNS visibility to the rest of the Net for my five static IP addresses and the domain name or names they represent.
Once I have a domain name, I can add aliases and extensions to define additional systems and services. For web access, a simple http://www.mySite.com/ produces a URL to access web pages. E-mail provided by an ISP is usually rather limited, often to five or fewer mailboxes. When you own the site and the mail router, you can have as many mailboxes as you wish. An outside user can send mail to me@mySite.com, and my own mail server will get it to my mailbox.
It is possible to start up an Internet site with typical ISP services in your home office. The availability of industrial-grade software for free is one of the key elements that makes this possible. Low-cost computers would not be enough if you had to add tens of thousands of dollars in license fees to the system. This quickly becomes prohibitive without free software.
From an educational perspective, this is an excellent platform for expanding skills. The OS and tools provide a high-quality system, with source code to delve into as necessary. Open standards are strongly supported and all major Internet development languages are available.
A variety of skills are related to developing and managing an Internet presence. This configuration can be used to study Internet site security, including common tools like Satan or Tripwire. These two tools help an administrator verify security and help detect breaks in activity, respectively. Other uses of the site once it's up include e-commerce and application server development. Using technologies like JDBC (Java Database Connectivity) and CORBA allow the development of significant commercial projects.
Of course, if you should outgrow these systems, it is possible to move up to RISC-based hardware with Linux, as it runs on DEC Alpha, PowerPC, SPARC and MIPS processors as well as Intel. The upgrade path to other hardware and other UNIX implementations is much easier from Linux than from an Apple, a Windows NT Server or proprietary network elements.
Tony Dean can be reached via e-mail at email@example.com.
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