It’s 8 a.m., one floor has lost internet access, and the engineer who set up the network no longer works with the company. Nobody knows which switch port that floor’s cable connects to, where the firewall password is kept, or what the switches’ management addresses are. A problem that proper documentation would have solved in half an hour now takes an entire workday.
Network documentation means getting network knowledge out of people’s heads and recording it somewhere secure and accessible, so that even a newly hired engineer can work with it.
What Should Be Recorded?
- Physical map: the location of racks, switches, access points and cameras on the building plan, and which patch panel port and switch port each network outlet connects to.
- Logical map: how the firewall, core and access switches, internet links and branch connections are linked; a simple diagram that shows the traffic path.
- Addressing: IP ranges, VLAN numbers and names, each network’s gateway, DHCP ranges, and a list of static addresses for servers and equipment.
- Equipment: the model, serial number, firmware version, management address and installation location of each device.
- Configurations: backup copies of the configuration files for the firewall, switches and routers.
- Service providers: internet account numbers, public IP addresses and support contacts for each provider.
- Access: who has access to the management panel of each device.
Never write passwords in a Word document or documentation spreadsheet. Keep them in a business password manager and only note their location in the documentation.
How to Record It
The tool matters less than consistency, but a few choices make the job easier:
- One central location: all documentation in one defined folder or system, not scattered across emails and people’s laptops.
- A consistent template: create a fixed template for each type of information, for example one table for addresses and one sheet for each switch.
- A simple diagram: draw the logical map with diagramming software; it doesn’t need to be pretty, it needs to be accurate.
- Specialized tools as you grow: for larger networks, open-source address and asset management tools such as NetBox keep addresses, racks and connections structured.
- An offline copy: keep a copy of critical documentation outside the network too; if the file server fails, the documentation should not become unavailable along with it.
Keeping It Current: The Hard Part
Outdated documentation can be more dangerous than none at all, because it creates false confidence. A few simple habits help:
- No change to the network, such as adding a VLAN or moving a cable, counts as “done” until it is recorded in the documentation.
- Keep a change log: what changed, when, by whom and why.
- Back up device configurations automatically and regularly; many firewalls and switches can send their configuration to a server on a schedule.
- Every few months, compare the documentation against the actual state of the network.
Common Mistakes
- Documentation that exists only in one person’s head or on their personal laptop.
- A map drawn in the first year and never updated.
- Unlabeled cables and ports; documentation without physical labels is useless in practice.
- Storing passwords in the documentation text.
Checklist
- The physical and logical network maps are up to date.
- The table of addresses, VLANs and DHCP ranges is recorded.
- Specifications and firmware versions of all equipment are available.
- Device configurations are backed up regularly.
- Internet provider details and support contacts are recorded.
- Passwords are in a password manager, and an offline copy of the documentation exists.
If your company network is undocumented or its documentation is outdated, ITPlus724 engineers can assess the network and produce complete, maintainable documentation for it.