Network documentation earns its keep the day the internet goes down and the person who set it up is on holiday. Here's what to capture, in an order that makes sense to whoever reads it next.
1. Internet connections
For each connection, record the provider, account number, circuit or service ID, the type (fiber, cable, DSL, 5G), the static IP block if there is one, the gateway, and the provider's support phone number. If there are two connections, write down which is primary and how failover works.
2. The firewall
Make, model, serial number, firmware version, management address, and how to reach the management page from outside if that's allowed. Store the admin password on the firewall's record, encrypted. Note any VPNs (site-to-site and remote access), port forwards and why each exists. A port forward with no reason next to it is one nobody will dare remove.
3. VLANs and the IP plan
A table works best:
| VLAN | Name | Subnet | Gateway | DHCP range | Purpose |
|---|---|---|---|---|---|
| 1 | Management | 10.0.1.0/24 | 10.0.1.1 | none | Switches, access points |
| 10 | Staff | 10.0.10.0/24 | 10.0.10.1 | .100-.250 | Computers |
| 20 | Voice | 10.0.20.0/24 | 10.0.20.1 | .100-.200 | Desk phones |
| 30 | Guest | 10.0.30.0/24 | 10.0.30.1 | .50-.250 | Guest Wi-Fi, internet only |
Add reserved addresses (printers, servers, the NAS) and the DNS servers handed out by DHCP.
4. Switches and access points
Model, management IP, firmware, location, and for switches, which ports go where: the uplink, the server, the phone system, the access points. If you use UniFi, Meraki or Auvik, this can be pulled in automatically, including port-level detail.
5. Wi-Fi
Each network name (SSID), its security type, its VLAN, and its password. Mark the guest network clearly, and note if the password is rotated on a schedule.
6. The diagram
A diagram should answer "how does traffic get from a desk to the internet?" at a glance: internet connections, firewall, core switch, other switches, access points, servers. The best diagrams are generated from the documented devices and the links between them, so they change when the documentation changes. Adding live monitoring status to the diagram turns it into a troubleshooting screen.
7. What talks to what
Before retiring a server or changing a firewall rule, you want to know what depends on it. A map of which computers connect to which servers, built from real connections over a few weeks, answers that far better than memory.
Keep it current
Networks change quietly: a new switch, a changed IP, a replaced access point. Sync network devices from your controllers, get told when a device changes or disappears, and review the rest quarterly. DokLocker does all of this, with UniFi, Meraki and Auvik integrations, diagrams that draw themselves, and a who-talks-to-whom map.