Ethernet Networking- P11

Ethernet Networking- P11:One of the biggest problems when discussing networking is knowing whereto start. The subject of computer networks is one of those areas for whichyou have to "know everything to do anything." Usually, the easiest way toease into the topic is to begin with some basic networking terminology andthen look at exactly what it means when we use the word Ethernet.
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Ethernet Networking- P11288 Ethemet Example 2: Small-But-Growing Real Estate The physical placement of equipment doesnt necessarly mirror the logical network arrangement. The router, the firewalls, and the switches will be mounted in a single rack that is placed in the current equipment room. The file server and fax server can also be placed in the equipment room. At least one, and perhaps two, of the desks that currently support stand-alone PCs can be removed. (One might be needed for the file server and another for the fax server.) What about security? Now that users can access e-mail and the multiple- listing services from their desktops, the equipment room can be locked. It can be secured with a smart-lock that uses an entry code. Only those in- volved in maintaining the hardware should have access to that room. The two hardware firewalls (specialized appliances running firewall soft- ware) provide significant protection. As mentioned earlier, the firewall that isolates the Web server admits Web requests but the firewall that isolates the internal network does not. (The internal networks firewall lets Web re- quests go out and admits responses to requests from the internal network, however.) Despite the firewalls, the file server should be protected with passworded user accounts. Because users on the internal network will be downloading e-mail, some of which will have attachments, they should have up-to-date virus and malware protection software, as well as personal firewalls. And, as always, user education about safe downloading, avoiding social engi- neering threats, and other secure behaviors is essential. Network Example 3: Small Law FirmSmall Law Firm (SLF) is a 55-year-old law firm that will be moving fromoffices on three floors of an old building into two floors of an office towercurrently under construction several blocks away from its current location.SLF has been given the opporunity to wire its floors for telecommunica-tions while construction is still in progress.SLF has 30 attorneys (10 of whom are partners), 20 legal secretaries, oneoffice manager, one bookkeeper, and one receptionist. Each partner has hisor her own legal secretary; the remaining legal secretaries work for two at-torneys each.In its current location, SLF has a 10Base-T Ethernet network that gives allclerical workers access to an e-mail server and a file server. Some of theattorneys also have PCs in their offices that they use for e-mail. 289290 Network Example 3: Small Law Firm The file server contains templates for common legal forms. When a form is needed, a legal secretary loads a copy of the form from the server and fills it in. The form is then printed and copied. All printed document copies are retained in filing cabinets. SLF sees the move to new quarters as an opportunity to upgrade its net- work and data processing in general. First, the attorneys would like to move away from the slower 10Base-T Ethernet to at least Fast Ethernet, with the possibility of using Gigabit Ethernet for the network backbone (in other words, for the connection between floors). Second, they would like to move to permanent electronic storage of documents and the retrieval of those documents over the network. This will involve placing document im- ages on high-capacity network attached storage devices. The network con- sultant working with the firm estimates that the initial document database will require two terabytes of storage and will grow by at least a half a terabyte a year. Third, SLF would like to consider an online subscription to a law book ser- vice that could also be available over the network through a shared Internet connection. In the long run, this would save the attorneys considerable money, given that SLF will need only one subscription to each law book series, rather than relying on attorneys to purchase their own hard copies. The idea is to eventually move to an all-electronic law library, including online access to legal search services such as Lexis from all offices rather than just from the library. Note: SLF understands that there may be some attorneys who purchase their own hard copies of law books anyway, given that they like the look of all those books on their office shelves. There are two ways to begin designing a network of this type. One is from the bottom up, where you start with the workstations and other end-user devices and then collect them into workgroups. You connect the work- groups with switches and then connect the entire network through some sort of backbone. Alternatively, you can work from the top down, where you begin with the backbone, moving to workgroups in general and finally to the individual end-user devices.The Internet, the Backbone, and Equipment Rooms 291 Most successful information technology projects today are designed using a nominally top-down approach. In truth, you cannot design a network without considering the end-user devices as you specify backbones, rout- ers, and switches. At the very least, you must have some idea of how many end-user devices (workstations and printers, for example) you will have and how they will interact.The Internet, the Backbone,and Equipment Rooms Because SLF is not occupying an entire building, it does ...