Network Operations · Topic 1 of 8
Network Documentation and Inventory
Learn the documents that support operations: physical and logical diagrams, rack and cable maps, floor plans, asset inventory, IPAM and SLAs.
- 4 min
- Physical diagrams show devices and cabling. Logical diagrams show subnets, VLANs and routing.
- A rack diagram shows device positions by rack unit.
- A floor plan shows building layout for placing jacks and access points.
What it is
Good documentation lets a team understand, change and repair a network without guessing. It records what exists, how it connects and what service level the business expects.
The exam asks you to name each document type, say what it shows and choose the right one for a task. Out of date documents are a risk, so keeping them current is part of the job.
How it works
Network diagrams
A physical diagram shows the real devices, cables, ports and locations. A logical diagram shows how data flows: subnets, virtual LANs (VLANs), Internet Protocol (IP) addresses and routing, without caring where the equipment sits. It can be drawn at Layer 2 (switches and VLANs) or at Layer 3 (routers and subnets).
| Diagram | Shows | Used for |
|---|---|---|
| Physical network diagram | Devices, cable runs, ports | Finding a cable, planning a move |
| Logical network diagram | Subnets, VLANs, routing paths | Understanding traffic flow and addressing |
| Floor plan | Building layout with outlets and equipment locations | Placing access points, jacks and rooms |
| Rack diagram | Position of each device in a rack, by rack unit | Adding equipment, checking space and power |
| Cable map and diagram | Which cable connects which port, and where it ends | Tracing a cable to a patch panel or wall jack |
A wiring or cable map is useful when a link fails, because it shows which patch panel port and wall jack belong together.
Wireless survey and heat map
A wireless site survey measures signal strength and interference in a building. A heat map draws that coverage on a floor plan in colors, so weak or dead areas are easy to spot.
Surveys are done before installation to plan access point placement, and after installation to confirm that coverage meets the goal.
Asset inventory
An asset inventory is a list of all hardware and software the organization owns, with enough detail to manage it.
| Element | Typical data |
|---|---|
| Hardware | Make, model, serial number, location, owner |
| Software | Applications and versions in use |
| Licensing | License type, number of seats, expiry date |
| Warranty and support | Contract end date, support level, vendor contact |
An accurate inventory helps with budgeting, patching, audits and replacement planning. It also reveals unknown devices that should not be on the network.
IP address management
Internet Protocol address management (IPAM) tracks which subnets and addresses are in use, which are free and to whom they are assigned. Many tools combine IPAM with Dynamic Host Configuration Protocol (DHCP) and Domain Name System (DNS) records.
IPAM prevents duplicate address assignments and makes planning new subnets easier.
Service level agreements
A service level agreement (SLA) is a contract between a provider and a customer that sets the expected service. It names measurable targets such as availability, response time and repair time, and it may include penalties.
For example, an SLA may promise a percentage of uptime in a month, or a time to fix a failed circuit. Documented requirements let the network team check whether the provider meets its promises.
Keeping documents current
Documentation should be updated as part of every change, stored where staff can find it, and backed up. Version control or a documentation system records who changed it and when.
What to remember for the exam
- Physical diagrams show devices and cabling. Logical diagrams show subnets, VLANs and routing.
- A rack diagram shows device positions by rack unit.
- A floor plan shows building layout for placing jacks and access points.
- A cable map traces which cable connects which ports.
- A wireless survey measures signal and interference. A heat map displays coverage.
- An asset inventory covers hardware, software, licensing and warranty support.
- IPAM tracks address space and prevents duplicate assignments.
- An SLA sets measurable service expectations such as availability and repair time.
Match the question to the document. "Which port does this cable end on" is a cable map, "which subnet does this VLAN use" is a logical diagram, and "where is the dead spot" is a heat map.
Common mistakes
Mixing physical and logical diagrams. A logical diagram can look tidy while the real cables are in different rooms.
Treating documentation as a one time task. An outdated diagram is worse than none, because it misleads troubleshooting.
Leaving warranty dates out of the inventory. Missing expiry dates mean devices lose support without anyone noticing.
Confusing an SLA with a policy. An SLA is an agreement with measurable targets between a provider and customer.
Tracking addresses in an unmanaged spreadsheet. It is easy to create duplicate assignments without IPAM.
Network diagrams and inventories reveal how the network is built. Store them securely and share them only with people who need them.
Check yourself
Work through these three.
Which document shows which VLAN uses which subnet?
A logical network diagram.
What does a heat map show?
Wireless signal strength across a floor plan, so weak areas can be found.
What does an SLA define?
Measurable service expectations such as availability and response or repair time.
Topic 1 of 8 in Network Operations
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