3.1 Explain the purpose of organizational processes and procedures
Documentation
📘CompTIA Network+ (N10-009)
In any organization, proper documentation is extremely important for managing, troubleshooting, and planning a network. Two of the most important types of network documentation are:
- Physical diagrams
- Logical diagrams
Both diagrams describe the network, but they serve different purposes and show different types of information. Understanding the differences is important for the Network+ exam.
What Is a Physical Diagram?
A physical diagram shows the real, physical layout of the network.
It focuses on the actual hardware, how devices are cabled, and where everything is physically located.
What Physical Diagrams Include
Physical diagrams commonly show:
- Network hardware
(switches, routers, firewalls, servers, racks, patch panels) - Cable types and paths
(Ethernet, fiber, cable numbers) - Port numbers / interface labels
- Rack layouts and equipment placement
- Physical locations
(IDF, MDF, server room, data center floor plan) - Power connections
(UPS, power strips) - Room numbers or building layouts
A physical diagram answers questions such as:
- Where is this switch located?
- Which cable connects this server to the switch and through which port?
- How are the racks organized?
Why Physical Diagrams Matter
They help IT staff:
- Maintain and replace hardware
- Trace cables during troubleshooting
- Plan equipment installation
- Understand physical dependencies
- Support audits and compliance
Common Format
- Floor plans
- Rack elevation diagrams
- Wiring diagrams
- Hardware topology maps
What Is a Logical Diagram?
A logical diagram shows how the network communicates, not where things are physically placed.
It focuses on network relationships, traffic flow, IP structure, and design.
What Logical Diagrams Include
Logical diagrams usually show:
- Network subnets and IP address ranges
(e.g., 192.168.10.0/24) - VLANs
(such as VLAN 10 – Staff, VLAN 20 – VoIP) - Routing paths
(how traffic travels through the network) - Firewall zones
(LAN, DMZ, WAN, guest network) - Network devices shown by function, not physical location
(Core switch → Distribution switch → Access switch) - Wireless networks
(SSID names, controller relationships) - WAN connections
(VPN tunnels, MPLS links, ISP connections)
A logical diagram answers questions such as:
- Which subnet does this device belong to?
- What VLAN is used for phones?
- How does traffic reach the internet?
- Which firewall controls this segment?
Why Logical Diagrams Matter
Logical diagrams are used for:
- Network design
- Planning changes or upgrades
- Security architecture
- Troubleshooting routing or VLAN issues
- Understanding how data flows
Common Format
- Topology charts showing connections by function
- Layered diagrams (Core → Distribution → Access)
- IP/VLAN maps
- Security zone diagrams
Key Differences: Physical vs. Logical Diagrams
| Feature | Physical Diagram | Logical Diagram |
|---|---|---|
| Focus | Hardware & cables | Communication paths & network structure |
| Shows | Devices, racks, ports, cable runs | IP subnets, VLANs, routing, traffic flow |
| Location-based? | Yes | No |
| Used for | Installation, cable tracing, maintenance | Design, troubleshooting traffic, security |
| Includes | Patch panels, floor plans, power | Subnets, VLANs, firewalls, routing protocols |
| Audience | Technicians, installers | Network engineers, security teams |
Why Both Diagrams Are Needed in an Organization
Organizations maintain both types because they complement each other:
- A technician might need the physical diagram to find the exact switch in the rack.
- A network engineer might need the logical diagram to identify which VLAN the user belongs to.
- A security admin uses logical diagrams to confirm firewall zones.
- A project manager uses both to plan upgrades.
Both diagrams ensure consistency, accuracy, and easier troubleshooting.
How They Are Used in Real IT Environments
Example 1: Troubleshooting Connectivity
- Logical diagram → shows the user is on VLAN 30 (Sales)
- Physical diagram → shows the cable from the user’s desk connects to Switch A, port 12
Together, they help technicians quickly isolate the issue.
Example 2: Planning a Network Upgrade
- Logical diagram → shows which subnets, VLANs, and devices will be affected
- Physical diagram → shows where the equipment is installed and what needs to be replaced
Example 3: Security Audits
- Logical diagram → used to confirm firewall rules and network segmentation
- Physical diagram → used to verify equipment location and access control
Best Practices for Physical and Logical Diagrams
To meet organizational standards and Network+ expectations:
1. Maintain Version Control
Always keep diagrams updated after configuration or hardware changes.
2. Use Standard Symbols and Labels
- Common icons for routers, switches, firewalls
- Clear cable labeling
- Standard IP and VLAN numbering
3. Store Diagrams in Shared & Secured Locations
Use organizational repositories such as:
- SharePoint
- Network drives
- Documentation tools (Visio, Lucidchart, draw.io, NetBox)
4. Keep Diagrams Simple and Clear
Avoid unnecessary detail that makes diagrams confusing.
5. Include a Legend
Helps readers understand symbols, colors, and notations.
Exam Tips (CompTIA Network+ N10-009)
Expect questions that ask you to:
- Identify whether a diagram is physical or logical
- Recognize what type of information belongs in each diagram
- Understand when each diagram is used
- Match diagrams with scenarios (e.g., cabling issue → physical diagram)
- Know that logical diagrams deal with traffic flow, subnets, VLANs, routing, and segmentation
- Know that physical diagrams show hardware locations, cables, racks, ports
Remember:
Physical = “Where things are”
Logical = “How things communicate”
