What is network documentation?

Network documentation refers to the processes for keeping track of the components present in your infrastructure. This means the hardware, cables, software versions, and services running on each host, which compose your internal network. It may be as simple as a spreadsheet with sparse information or as complex as a dedicated network documentation tool that automates the process. Most companies opt for an in-between solution, depending on the size of their networks.

Numerous types of collected data may compose a company's network documentation. Certainly the bare minimum is a list of the hardware that is in service or kept as a backup. This means the vendor, hardware version, exact model, and all the components’ names and models that make up each device. Switches, routers, bridges, network cables, and servers all compose the hardware part of network documentation.

The software part is the most complex and ever-changing one. Software that rarely changes, such as firmware, is not the only type to be documented; all the services running on servers, hosts, and network devices make up the whole software network documentation. These data are subject to frequent changes, especially in the case of cloud environments, making their tracking an impossible task to perform manually.

This is the primary reason why network documentation software exists. Not only to automate the manual tasks that would otherwise become outdated every day but also to streamline the whole process.

Why is network documentation important?

Network documentation is another important part of network monitoring. The reason is simple: by knowing what is present in your infrastructure, it can be better monitored. But this isn’t the whole story.

Imagine a case where a new engineer joins your company and there’s no existing network documentation. This poses a problem for the new hire; it is not possible for him/her to quickly discover how your infrastructure is set up. Taking time to learn how it is all interconnected becomes a long and error-prone task that would have been avoided with clear network documentation. Even sparse notes by previous engineers would have helped, even if far from optimal as documentation goes.

Ignoring the benefits of network documentation therefore results in wasted time and money. A good network documentation tool would have kept the status of the infrastructure constantly updated, leaving the engineers to work on more productive tasks.

It is not just about saving time and money, though. It may be occasionally necessary to do an audit due to internal procedures or external compliance. Having a set of up-to-date network documentation makes it much easier.

Networking and network topology planning requires the purchase of software or hardware. These are high costs that need to be planned and budgeted with justified reasons. Without proper network documentation, you end up just guessing whether new resources are needed or already present and largely unused. This situation stands in stark contrast with having advanced network monitoring software that can inform you of bottlenecks and reaching capacity in any area of your network. Knowing what you have and where it has reached its limits makes planning for upgrades a breeze.

Key advantages of network documentation

It is clear by now how network documentation, and thus implementing a network documentation tool, is important for clarity and streamlining processes, both internal and external.

Network documentation is advantageous in many ways. When troubleshooting issues, having a history of both software and hardware, as well as how it all interconnects, is of great importance in identifying what broke what. Even keeping a simple network documentation template by hand would be sufficient for this scope, albeit quite cumbersome.

Network documentation benefits the keeping of up-to-date SOPs (Standard Operating Procedures). If documentation is standardized, through automation or by establishing a clear template, SOPs can be more easily based on it. SOPs can be followed independently too, but having a network documentation means that can be built upon what exists, in any given moment, without any speculation, would be a more convenient system.

Further, leaving the knowledge of how your network works to one or two key people can rapidly become a nightmare when they are not available when you need them. A network documentation tool can substitute them and allow anyone with normal IT knowledge to step in.
Moreover, capacity planning is no longer a guessing game when you have your network topology updated thanks to network documentation software. Planning with components and services that are either not present anymore or not registered as in service means a disconnect between planning and the current infrastructure. This leads to all sorts of issues and wasting of money.

In the end, having an as-complete-as-possible image of what is operating in an infrastructure is vital in order to monitor it properly, to create procedures about it, and to avoid wasting resources. Network documentation may not be the most glamorous process in IT, but it is nonetheless essential for the proper use of resources, including human ones.

What should be documented?

Procedures for documentation differ from company to company. Broadly speaking, there are a few key steps to every good network documentation process.

Network documentation policy

First, a policy about what to document should be in effect and regularly updated. The policy can be based on one of the many network documentation templates that exist or created from scratch. It is important that it is followed and that it is comprehensive.

Therefore – and here automated network documentation software can help – having a topology map of your network is the first step to building a network documentation system. If that topology is visual, like in Checkmk, all the better. But even a simple list can be a valuable starting point to creating your first network documentation.

Network Topology for LLDP

Hardware and software to document

Specific data to be documented vary. A bare minimum would be all the hardware that is in operation, with their versions, configurations, how each device is connected to the network, whether a particular device requires a password, if a backup exists, and the firmware version. If diagrams of the network exist, they should also be included.

Once hardware is covered, software is next. A complete network documentation process should collect every software/services version, what they are running on and where, their configurations, and if backups are present and where.

If cloud or virtual services are used, they as well should be part of the final documentation. These must be automated through a network inventory documentation tool due to their volatility.
Next, how everything is interconnected should be documented as well. Starting from the cable plan and how cloud services are operating, to the server rack layout and Wi-Fi diagrams. IP allocation tables and Active Directory setup should not be forgotten either, and the same goes for DNS and routing tables.

Ideally, everything that would allow rebuilding the infrastructure from scratch, without any previous knowledge of it, should comprise network documentation.

Last, it is important to document how the network documentation is created. If network documentation software is used, this may simply mean brief steps on how to install and set it up. If a more manual approach is chosen, this task may grow into a set of wiki pages or the like, documenting how to collect all the above-mentioned data.

Network documentation for better network monitoring

Network documentation offers many advantages, as we have seen. It would not often be implemented if it was not automated, though. Network documentation tools are there to help companies set up the documentation right, and with ease. Making it simpler to collect the info on your hosts and services and presenting the network as an easy-to-read interface are highly-desirable features that help with network documentation.

These are naturally integrated into network documentation software like Checkmk. Thanks to its Auto-Discovery, hosts and services are quickly added to monitoring and thus entered into its internal network documentation. With reporting available, what is shown in Checkmk can be exported as proper documentation, making translating the monitoring capabilities of Checkmk into network documentation simple.

Network topology is part of Checkmk as well, and a great tool to visually show your network documentation. And it does not stop at showing it; the topology can be interacted with, expanded at will, and customized and perfected to your tastes. It takes the functions of a network inventory documentation tool and pairs them up with complete network monitoring capabilities. These features make network documentation fairly straightforward, and Checkmk is a great tool to implement it.

FAQ

What is a network documentation policy?

Network documentation policy refers to the internal requirements for network documentation. It is a document that establishes what is to be included, how it is to be documented, and how to keep network documentation updated. This policy is especially necessary when compiling network documentation manually, but it is also important when automated methods are set up. Network infrastructure documentation templates exist for a quicker start.

How do you write network documentation?

Network documentation is written in many different ways. It may be a single document or a series of many, interlinked, as in a wiki. Network documentation examples are useful for getting started quickly, and then you can adapt them to your own needs. Network inventory documentation tools can create an initial inventory of hosts and services to be exported as a document and worked on.