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e -server magazine

March 1996: Volume 11, Number 4

Communicating with Sam

Internet Security

By Sam Johnston

From the questions submitted, the selected issue to be addressed in this issue is:


ur network recently migrated from an X.25 network with SDLC communications to a routed frame relay network. The objective of this project was to provide a cost effective solution for an enterprise E-mail system. Now our company wants to explore the Internet and utilize it to provide us with strategic advantages over our competition. We want to allow our users access for communicating with customers and suppliers, and provide a home page for our customers. Can we utilize our network and still maintain security?


t seems that everybody in all industries are talking about the Internet. Your concern about security is not unique to your business needs. In fact, Internet security solutions is one of the fast growing markets in the I/T industry. IBM, for example, has recently announced many new product offerings to address this concern. In fact security is so important that vendors like IBM have placed Internet product development at the top of their strategic agendas. The revolution of "Network Centric Computing" is expected to explode in 1996. The development of a secured Internet is instrumental in supporting a Network Centric world. Of further interest is the strategic positioning of both the AS/400 and Lotus Notes in a Network Centric environment. However, this is a topic for another discussion.

From a network communications viewpoint, the answer to both your questions is yes. You obviously have completed the business planning portion of your project and understand the applications concepts. For your communications and networking design, the first step is to obtain a corporate Internet address for your company.

The entire Internet utilizes a standard of IP (Internet Protocol) for the transportation of communications. Therefore, your company address for the Internet is simply an IP address. This IP protocol standard for the Internet is the same standard utilized your WAN for router to router communications. There are three main categories of IP address (A, B & C).

An Internet address can be obtained by registering your company with the Internet through an Internet service provider. Generally, service providers sell three offerings: 1.) a "C" address, 2.) a "sub-net C" address, or 3.) a host address. Prior to selecting a provider and the appropriate service offering you will want to plan some key requirements. Some of the issues to consider are:

  1. Other Internet services you will require - evaluate the providers based upon all of your requirements.
  2. The number of host connections required.
  3. Your Enterprise IP addressing scheme and migration plan.

For your connection to the Internet, utilize your head office router. This method will provide a central connection to the Internet provider and will allow you to control access and long distance charges for Internet use, providing the Internet provider is local to your head office. Additionally, one of the features of the IP standard is its address filtering capabilities. This will provide you a measure of basic security by filtering access to and from your network. Also by utilizing the head office router, you will be able to administer and manage the filtering from a central location. For more advanced security, firewall products may need to be investigated.

The Internet is a complex and exciting technology that promises to have some profound long-term impact on how we do business. Although the applications are limitless, the technology is not. A finite number of Internet address exist, and the supply is quickly being depleted. The full potential of the Internet will not be understood for some time, but this technical limitation is forcing people to develop an Internet strategy today to avoid being left out in the future. T < G

Note: Any TUG member wishing to submit a question to Sam can e-mail or forward their typewritten material to the TUG office, or to Intesys. We would be pleased to publish your question and Sam's answer in an upcoming issue of the TUG/400 e-server magazine.