SDM - May 2008 - (Page 109)

Security NetWorkings by David Engebretson, Contributing Technology Writer TIPS FOR CURING CONFUSION Getting a Computer on the Network the Right Way Sometimes it’s the simple things that can confuse us the most. Just the act of getting a computer to communicate on a local network can create some situations and problems that can confound uninformed technicians. Let’s take a look at some common scenarios and see what it takes to get a laptop or desktop PC onto a network the right way. Why would you want to disable a network interface? Windows gives you the capability of having more than one network interface enabled simultaneously. This is not necessarily a good thing. During hands-on training classes, I’ve seen that having two interfaces running at the same time can cause confusion within the computer, and communications to specific devices will not work, even though everything is properly programmed. So I turn off every network interface except the one that I want to use at a particular moment. Let’s look at some examples of IPCONFIG reports, and I’ll describe what’s going on. What does this mean? This response to IPCONFIG means that no network interface is enabled. So turn on the one, wired or wireless, that you want active. TURN ON THE NETWORK To establish network communications, the NIC, or network interface card, must be “enabled” or turned on. NICs can be either wired Ethernet or wireless Wi-Fi. To do this, you can click “Start,” then “Control Panel,” then “Network and Internet Connections,” then “Network IP ADDRESSING ISSUES Connections.” You will see a window In our Networking 201 hands-on training course, we teach our students to like this: check the IP address of their laptop often during a testing or troubleshooting session. It is easy to get ahead of yourself Here you can right-click the net- and forget what you have done in relawork interface you are interested in, tion to the IP address of your computer. highlight “Enable” and click to turn Using IPCONFIG at the command line on that device. These commands are will quickly tell you what is the status toggles, so it is the same process to and address of the network interface in your computer. disable a particular interface. Engebretson's Book of the Month Thunderstruck by Erik Larson, Three Rivers Press A great read that blends the story of Marconi’s commercialization of radio communications with a sordid murder in London, culminating in the perpetrator getting caught in the middle of the ocean aboard a liner equipped with Marconi’s system. The Marconi sections provide a detailed description of escription the trials and tribulations of getting a new technology off the ground. This IPCONFIG response signifies that your network card is enabled, but your computer is set to ask for a DHCP (dynamic) address and there is either no DHCP server or the DHCP server is turned off. The network interface is asking for an address, but there is no dynamic address provided. In this case, you would need to select a static IP address that will work on the network you want to connect to, and you’ll have to manually put in the IP address in your computer. You can reach the screen that you need by following the path detailed above to reach the network interfaces, rightclick on the one you want, and select “Properties.” This brings you to the Local Area Connection box, where you pull down the center selections until you see “Internet Protocol TCP/IP,” which you highlight and click “Properties” once more. You’ll see a window called “Internet Protocol TCP/IP Properties” where you’ll click the button that says, “Use the following IP address” and the fill-in boxes will become active. Put in the IP address you’ve selected, along with the proper subnet mask and default gateway, and then click “OK” twice to close these windows. May 2008 109

Table of Contents Feed for the Digital Edition of SDM - May 2008

SDM - May 2008 Contents Editor’s Angle Exclusive ISC West Coverage Stanley Convergent’s Newest Acquisition Cisco Introduces New IP Cameras, Expands Physical Security Solution Portfolio Ionit Technologies Partners with Walgreens; Places DVR Systems in Stores Nationwide Pennsylvania-Based Security System Providers Merge Custom Home Electronics Distributor Inks Distribution Agreement Security and the Law Integration Intelligence 18th Annual SDM 100: Double Digits Fire Systems: State of the Market Addressable Fire Control Systems Storage: Where Can We Put All This? Central Station Managed Access Technology at Work 5-Minute Tech Quiz Technology Solutions & Skills Security NetWorkings SDM Marketplace Classifieds

SDM - May 2008

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