Documenting: My LAN Part 3

Published on April 6, 2022 at 6:37 pm by LEW


An often overlooked part of LAN design is documentation. For most small home LAN’s, documentation is not a necessity. However if you are planning on adding servers, multiple network segments, or other specialized functionality I would urge you to consider doing some documentation.

It does not have to be anything really extensive. It could be as simple as a network diagram, or a list of components with their specs. When installing or expanding, having something to reference can make network tasks and troubleshooting much easier.

It can also make it easier for someone else to troubleshoot your network if that need ever arises.

What to include?

At a minimum I would suggest documenting all equipment user names/passwords, type, static IP addresses, and any custom settings (like DHCP range for example). You should also document your ISP contact information. If your network is more than just a few components, I would also highly suggest a simple network diagram.

You can, of course, get as detailed/complex as you want and document things like OS type, firmware versions, component model and serial number, last update, ext.

There is really no limit to how detailed you can get. However consider the law of diminish returns. This is an economics law, but can be applied in our situation. At some point your return on your investment of time and energy will decrease to the point where it is not worth further investment. Or to put it simply, some items on your network are not worth documenting, as you will never use it, or it can be subsumed from other information.

Practical Example

Since I am in the process of building a network, I will walk though what I have done for documentation. I keep my network documentation on my main computer, as well as on a USB flash drive. Being on my main computer, it is also stored in my backups.

Below are a list of steps in no particular order that I like to go through.

User/Service Manual Review: This one can be a bit passe in this day and age. But if not included with a product, I usually go on line to find if one exists. Specifically I am looking for default password, username, IP address, SSID’s, etc. I keep these in a spreadsheet crossing to manufacturer and model. You would be surprised how many times I fixed a component by doing a factory reset, at which point it is better to have this information at hand, rather than guessing or scrambling to look it up.

You can keep these in an un-encrypted file, as default settings are usually easy to find on line. And as part of basic network security, you should be changing the default passwords anyway.

Password List: You should also keep an encrypted list of your actual passwords and user names, if your memory is bad, like mine. It is also bad security practice to use the same password for everything. If you only have one or two pieces of equipment that need passwords, you can probably remember them. But if I have more than that, I record them in an encrypted file, so I only have to remember one password.

Components: If you are ruining any serves, you will want to keep some documentation on theses as well. Start with the name of the server, then follow up with services it provides (servers can have a single function, or they can be multi functional). Routers, smart Switches, and VPNs are other items you will want to have some documentation on as well.

Other components like hubs and regular switches do not need specific documentation, other than they exist. They perform a simple function, and cannot, in most cases, be changed.

Network Diagram: This can be as simple or as complex as you want. At a minimum it should include components with IP addresses and connection types. I will spend the rest of this post talking about network diagrams, as other than password files, that will be your main piece of documentation.

Diagramming Network Components

The following are suggestions to hopefully give you some ideas about how you would like to go about diagramming your network. As stated, the more complex the network the more a diagram is needed. Simple networks probably don’t require a diagram, or at least nothing more than a simple hand drawn diagram, as long as it tells you the information you need to know. Below is a simple example of my early network, before getting into home labs, servers, and more complex networks. It is pretty simple.

Simple network

Here is another example using a slightly different style and more components.

More complex NetworkHere is a zip file of my SVG network icons. Feel free to use it.



We have discussed how to document a network. You can get as simple or complex as you need. Documentation servers three basic purposes. First to help you keep things organized, second to aid when you have an issue, and third to have a record of what your network setup is.

In the next post, I will start discussing specific components.

Planning: My LAN Part 1

Naming: My LAN Part 2

Documenting: My LAN Part 3

Components: My LAN Part 4

Router: My LAN Part 5

Access Point: My LAN Part 6

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