- Client operating system exams
- Server operating exams (core networking and design exams)
If you are pursuing a Microsoft certification in any of their network series of exams, at some point or another you are going to come across Domain Naming Systems (DNS). In the world of IT systems and networking, DNS is what makes the world go round; there is no avoiding it. So if you have heard of it vaguely and hoped it was something you could get by without knowing, then sorry, there is no escape from this one. And if you know DNS and even work with it regularly, then you most likely stopped reading after the title. However the purpose of this article isn’t to teach you DNS in order for you to pass a Microsoft exam; don’t look at this as a study guide or as a replacement for reading your doorstop-thick study manuals for whichever exam you are looking to take. Instead, the aim is to break the topic of DNS down and to highlight the importance of DNS, and what it is about DNS that Microsoft will expect you to know.
Client operating system exams
The simplest way of summing up DNS is that it is a database which contains the mappings of hostnames to IP addresses. Well that seems fairly straight forward; good luck with your exam... Okay, even at this level, you do need to know a bit more. However, this is one of the key points to keep in mind as you progress with your studies of DNS, as it can get lost in the haze once you get into deep configuration of a DNS console.
It is important to understand at this level the process that DNS takes to match up host names to IP addresses, which in the case of a standalone computer is the system’s HOST file. Nothing shows the simplicity of DNS better than the HOSTS file, and this will give you a chance to view DNS as it was first managed and implemented manually before dynamic DNS came along. Get used to calling computer names hostnames from here on in.
It is also still common within Microsoft examinations to make reference to the Windows Naming Service (WINS), which is the Windows version of DNS used before the internet made it an unusable and insecure option outside of the local network. Microsoft still likes to mix the two up a bit, with questions on their similarities and differences being the most obvious. WINS is still relevant in Windows networks today, however, so make sure you know it, including the LMHOST file (the WINS equivalent of the HOST file), the various broadcast node types it uses for name resolution, and the importance of NetBIOS, particularly within TCP/IP properties.
In fact, the most likely time you will come across DNS within the client exams is when you are configuring a computers TCP/IP properties. A core setting is always the DNS server. Know that you can set more than one DNS server and that here you can specify the order of DNS suffixes applied to the computer. This will inevitably lead you into covering Fully Qualified Domain Names (FQDN) and how this is used in name resolution, and its relevance in a fully functional domain. By the end of the client operating system examination, you should understand that DNS takes the computer name (hostname), combines it with a domain name, and at the core of it is the root, represented by a full stop. This is then mapped to the computers IP address so that when the FQDN is referenced, name resolution occurs. The client level doesn’t demand much more knowledge than that, but it does pay to read around the topic.