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.
Practical Task Scheduling Deployment
July 20, 2016 12:00 pm CDT
One of the best things about the UNIX environment (aside from being stable and efficient) is the vast array of software tools available to help you do your job. Traditionally, a UNIX tool does only one thing, but does that one thing very well. For example, grep is very easy to use and can search vast amounts of data quickly. The find tool can find a particular file or files based on all kinds of criteria. It's pretty easy to string these tools together to build even more powerful tools, such as a tool that finds all of the .log files in the /home directory and searches each one for a particular entry. This erector-set mentality allows UNIX system administrators to seem to always have the right tool for the job.
Cron traditionally has been considered another such a tool for job scheduling, but is it enough? This webinar considers that very question. The first part builds on a previous Geek Guide, Beyond Cron, and briefly describes how to know when it might be time to consider upgrading your job scheduling infrastructure. The second part presents an actual planning and implementation framework.
Join Linux Journal's Mike Diehl and Pat Cameron of Help Systems.
Free to Linux Journal readers.Register Now!
- SUSE LLC's SUSE Manager
- My +1 Sword of Productivity
- Murat Yener and Onur Dundar's Expert Android Studio (Wrox)
- Non-Linux FOSS: Caffeine!
- Managing Linux Using Puppet
- Doing for User Space What We Did for Kernel Space
- Tech Tip: Really Simple HTTP Server with Python
- SuperTuxKart 0.9.2 Released
- Parsing an RSS News Feed with a Bash Script
- Rogue Wave Software's Zend Server
With all the industry talk about the benefits of Linux on Power and all the performance advantages offered by its open architecture, you may be considering a move in that direction. If you are thinking about analytics, big data and cloud computing, you would be right to evaluate Power. The idea of using commodity x86 hardware and replacing it every three years is an outdated cost model. It doesn’t consider the total cost of ownership, and it doesn’t consider the advantage of real processing power, high-availability and multithreading like a demon.
This ebook takes a look at some of the practical applications of the Linux on Power platform and ways you might bring all the performance power of this open architecture to bear for your organization. There are no smoke and mirrors here—just hard, cold, empirical evidence provided by independent sources. I also consider some innovative ways Linux on Power will be used in the future.Get the Guide