📘 02-03: Network Documentation¶
💡 Why Document?¶
Documentation makes troubleshooting faster, onboarding easier, audits possible, and changes safer. Stale documentation is worse than none — update it after every change.
📌 Types of Documentation¶
| Document | Shows |
|---|---|
| Physical network diagram | Actual devices, ports, cable runs, locations |
| Logical network diagram | IP addressing, subnets/VLANs, routing, data flow |
| Rack diagram (elevation) | Device positions (U by U) in each rack |
| Wiring/labeling scheme | How cables, jacks, ports, and racks are labeled |
| IPAM records | Assigned IPs, subnets, hostnames, DHCP/DNS data |
| Baseline | Normal performance metrics for comparison |
| Inventory / asset list | Devices, models, serials, firmware, warranties |
📌 Labeling¶
Consistent labels on cables, patch panels, jacks, and racks let a technician trace connections quickly and reduce errors during changes. A good scheme is unambiguous and standardized.
📌 Baselines¶
A performance baseline records normal traffic, utilization, latency, and error rates so that anomalies (spikes, slowdowns, breaches) are recognizable by comparison later.
📌 IP Address Management (IPAM)¶
IPAM tracks which addresses/subnets are assigned, reserved, or free, along with DNS/DHCP data — preventing IP conflicts and simplifying audits.
Tip
Key idea — Keep physical + logical diagrams, labels, IPAM, and a baseline current. Documentation is only valuable if it is accurate — update it as part of every change.
See also: Change Management & Agreements, DHCP
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