- Part 1 - Mapping the OSI Model
- Part 2 - VLANs
- Part 3 - IP Routing
- Part 4 - Link Aggregation and Teaming
- Part 5 – DNS
- Part 6 - Ports, Sockets, and Applications
- Part 7 - Bindings
- Part 8 - Load-Balancing Algorithms
Why It MattersIn the Windows NT 4.0 days, the Microsoft Certified Systems Engineer exam track required passage of “Networking Essentials” and the electives included a TCP/IP exam. Neither of these exams had a corollary in the Windows 2000 track and, although I haven’t kept up much with the world of certification since the Windows 2003 series, I’m fairly certain that networking has largely disappeared from Microsoft certifications.
That’s both a blessing and a curse. Basic networking isn’t overly difficult and a working knowledge can be absorbed through simple hands-on experience. More advanced, and sometimes even intermediate skills, can be involved and require a fair level of dedication. If all you really need to do is plug a Windows Server into an existing network and get it going, then a lot of that is probably excess detail that you can leave to someone else.
There are certification, expertise, and career tracks available just for networking, and the network engineers and administrators that earn them deserve to have their own world separate from system engineering and administration. Learning all of that is burdensome for systems administrators and is unlikely to pay dividends, especially with the risk of skill rot.
The downside is that it’s no longer good enough to know how to set up a vendor team and slam in some basic IP information. Too many systems people have ignored the networking stacks in favor of their servers and applications and are now playing catch-up as integrated teaming, datacenter bridging, software-defined networking, and other technologies escape the confines of netops and intrude into the formerly tidy world of sysops.
The first post of this series will (re)introduce you to the fundamentals of networking that you will build the rest of your Hyper-V networking understanding upon.
The OSI ModelIf you’ve never heard the phrases “All People Seem To Need Data Processing” or “Please Do Not Throw Sausage Pizza Away”, then someone along your technical education path has done you a great disservice (or you learned the OSI model in a non-English language). These are mnemonics used by students to drill for exams that test on the seven layers of the OSI model, which obviously worked because I can still recall them fifteen years later:
- Data Link
The reason that we have two mnemonics is because traffic travels both ways in the model. If your application is Skype, then the model covers your voice being broken into a rush of electrons (from seventh down to first layer) and back into something that might sound almost like you on the other side of an ocean (from first up to seventh layer).
The OSI model is a true model in that it does nothing but describe how a complete networking stack might look. In practice, there is nothing that perfectly matches to this model. The idea is that each of the seven layers performs a particular function in network communications, but only knows enough to interoperate with the layer immediately above and immediately below. So, no jumping from the physical layer to the presentation layer, for instance.
I’m not going to spend a bunch of time on the seven layers. There are a lot of great references and guides available on the Internet, so if you really care, do some searching and find the resource that suits your learning model. If you’re in systems or network administration/engineering, layers six and seven will likely never be of any real concern to you. You might occasionally care about layer five. We’re really focused on layers one through four, and that’s what we’ll talk about.
Use the following diagram as a visual reference for the upcoming sections: