by Emmett Dulaney
3/29/2006 -- There are a few certification exams that I think fondly of, or find a real purpose for, and Network+ is one of those. I became a fan of this single-exam credential when it first debuted in the late '90s and was embraced by a number of vendors as a substitute for the basic networking test within their proprietary tracks. This vendor-neutral multiple-choice exam was the first one released by CompTIA that had the potential to serve as a key element in certifications from Novell, Microsoft and others (and has). To keep it current, it was revised in 2002 and again in 2005. As of this writing, it is estimated that there are currently 140,000 individuals holding this certification.
Although I already held the certification (and all CompTIA titles are good for life -- you won't need to renew this if you pass it), I retook the exam recently to see what was different with the 2005 objectives and if it was still as good as I remembered it. While I was disappointed that grammar still appears to be a problem on some questions (how hard can it be to run a spelling and grammar check?), the updates make sense and the exam remains a valuable entry-level starting point toward higher-level, proprietary certifications.
All the multiple-choice questions on the exam are short and direct. In fact, there are times when you can cause yourself a problem by trying to read more into the question than is there because they are so short. The best approach to take is to read the question quickly, take it at face value, look at the answer possibilities, choose one and move on before you have a chance to talk yourself out of the right answer.
CompTIA recommends a candidate have at least nine months experience in the field before attempting the exam, but there is no requirement for this. In actuality, nine months should be viewed as a bare minimum. You will also find the exam much easier if you have experience taking other CompTIA exams, namely those for A+, Server+ or i-Net+ since there is a fair amount of overlap in the topics they cover.
A large number of books and self-study aids exist for this exam, but most of the objectives can be researched through a good search engine and hands-on experience. By doing so, you can save the cost of the training materials and use them toward the next step in your studies.
Below I briefly cover just some of the Network+ objectives to give you an idea of exam's topic areas. As mentioned, you'll want to download the complete objectives from CompTIA's Web site, available here.
At the very basic level, you should know public networks use public IP addresses that are assigned to them. You must have a public address (at least one) to communicate on the Internet. Within each of the network classes, a range has been set aside as private. Private networks use addresses within these ranges and do not communicate directly with the Internet, although they may do so indirectly through a proxy or network address translation (NAT) server. The range, based upon address class, set aside is:
Additionally, Microsoft has added to many of its operating systems a default range for clients if automatic IP addresses are not assigned. If a client is set to receive address configuration from a DHCP server and the DHCP server cannot be found, an address in the range of 169.254.x.x will automatically be assigned. This allows the clients on the network to communicate with each other while the DHCP server is down.
Any networking technician worth their salt will make sure they have their subnetting skills down -- make sure you do, too.
Not only should you know the core TCP/IP applications, but also the troubleshooting tools that tend to be available in every implementation. These range from arp to winipcfg. Anyone at a Network+ level should be very familiar with these tools, the results they display, and when to use one of them instead of another.
When two or more LANs get together, they form a WAN. You should be
readily able to identify all the characteristics of the various WAN
technologies from switching to T1 and T3 lines.