Lab 01 — Build Your Network+ Lab Environment

Mission Information

Item	Details
Lab	01
Lab Name	Build Your Network+ Lab Environment
Track	CompTIA Network+
Difficulty	Beginner
Estimated Time	90–120 minutes
Primary Role	Network Technician / Junior Network Administrator
Environment	Isolated Virtual Networking Lab
Primary Systems	NETPLUS-ADMIN, NETPLUS-CLIENT01, NETPLUS-SERVER01
Primary Tools	Virtualization Platform, Wireshark, Command-Line Networking Tools
Skills	Virtual Networking, IP Addressing, Connectivity Testing, Network Interfaces, Basic Troubleshooting

Mission Objective: Build a reusable Network+ lab environment that will be used throughout the remaining hands-on labs.

Mission Scenario

You have joined GHC Enterprise as a junior network technician.

Before you can begin configuring VLANs, routing, DHCP, DNS, wireless networks, or troubleshooting enterprise connectivity, the networking team asks you to build a controlled practice environment.

Your lab must allow you to:

Create multiple systems
      ↓
Place them on isolated networks
      ↓
Configure IP addresses
      ↓
Verify connectivity
      ↓
Generate network traffic
      ↓
Capture packets
      ↓
Troubleshoot connectivity problems

You will build a small virtual enterprise network consisting of:

NETPLUS-ADMIN
NETPLUS-CLIENT01
NETPLUS-SERVER01

and prepare the environment for the entire Network+ practical series.

Mission Objectives

By completing this lab, you will be able to:

understand the purpose of an isolated networking lab
create virtual machines
understand virtual network adapters
create a private virtual network
configure hostnames
assign static IPv4 addresses
identify IP address information
identify MAC addresses
verify Layer 3 connectivity
test localhost networking
understand default gateway concepts
verify DNS configuration
install and verify Wireshark
capture basic network traffic
troubleshoot common initial lab issues
document a simple network topology

1. Lab Architecture

Your initial environment will look like:

              NETWORK+ LAB

        +----------------------+
        |    NETPLUS-ADMIN     |
        |     10.10.10.10      |
        +----------+-----------+
                   |
                   |
          Virtual Lab Network
             10.10.10.0/24
                   |
        +----------+-----------+
        |                      |
        |                      |
+-------+--------+    +--------+--------+
| NETPLUS-CLIENT01|   | NETPLUS-SERVER01|
|   10.10.10.20   |   |   10.10.10.30   |
+-----------------+   +------------------+

For this first lab, all systems will exist on the same subnet.

2. Recommended Systems

Create three systems.

NETPLUS-ADMIN

Purpose:

Network Administration
Packet Capture
Troubleshooting
Network Testing

Recommended operating system:

Ubuntu Desktop
or
Windows

Recommended resources:

2 CPU
4 GB RAM
30 GB Disk

NETPLUS-CLIENT01

Purpose:

Client Connectivity Testing
DHCP Testing
DNS Testing
VLAN Testing
Troubleshooting

Recommended operating system:

Windows 11
or
Windows 10

Recommended resources:

2 CPU
4 GB RAM
30–40 GB Disk

NETPLUS-SERVER01

Purpose:

DNS
DHCP
Web Services
Network Services
Linux Troubleshooting

Recommended operating system:

Ubuntu Server

Recommended resources:

2 CPU
2–4 GB RAM
25–30 GB Disk

3. Choose a Virtualization Platform

You may use:

VirtualBox
VMware Workstation
Hyper-V

The exact platform is less important than understanding:

Virtual Machine
      ↓
Virtual Network Adapter
      ↓
Virtual Switch
      ↓
Network Segment

4. Understand Virtual Network Modes

Common virtualization networking modes include:

NAT

Virtual Machine
      ↓
Virtual NAT
      ↓
Host
      ↓
Internet

Useful when a VM requires internet access.

Bridged

Virtual Machine
      ↓
Physical Network

The VM behaves like another device on the physical network.

Host-Only

Host
  ↕
Virtual Machines

Usually isolated from the external physical network.

Internal / Private Network

VM
↕
VM
↕
VM

Useful for isolated networking labs.

For this course, prefer:

Private / Internal Lab Networking

for traffic-generation exercises.

5. Create the Network+ Lab Network

Create a virtual network named:

NETPLUS-LAB

Use:

Network:
10.10.10.0/24

The network design will be:

10.10.10.0
      ↓
Network Address

10.10.10.1–10.10.10.254
      ↓
Usable Hosts

10.10.10.255
      ↓
Broadcast Address

You will study these concepts in detail in Lab 03.

6. Configure VM Network Adapters

Connect each VM to:

NETPLUS-LAB

The logical result should be:

NETPLUS-ADMIN
      |
      |
NETPLUS-LAB
      |
      +----------------+
      |                |
NETPLUS-CLIENT01   NETPLUS-SERVER01

7. Optional Internet Adapter

For software installation, you may temporarily add:

Adapter 1:
NAT

Adapter 2:
NETPLUS-LAB

Conceptually:

                 Internet
                    |
                   NAT
                    |
          +---------+---------+
          |     NETPLUS-ADMIN |
          +---------+---------+
                    |
              NETPLUS-LAB

For investigation exercises, you can disable the NAT interface if internet access is unnecessary.

8. Configure Hostnames

Configure:

NETPLUS-ADMIN
NETPLUS-CLIENT01
NETPLUS-SERVER01

Verify on Windows:

hostname

Verify on Linux:

hostname

Record the results.

9. Configure the IPv4 Addressing Plan

Use:

System	IPv4 Address	Subnet Mask
NETPLUS-ADMIN	10.10.10.10	255.255.255.0
NETPLUS-CLIENT01	10.10.10.20	255.255.255.0
NETPLUS-SERVER01	10.10.10.30	255.255.255.0

CIDR notation:

/24

For now, leave the lab-only interface default gateway blank unless you have added a router.

10. Configure NETPLUS-ADMIN on Linux

First identify the interface:

ip addr

or:

ip link

You may see:

ens33
ens160
enp0s3
eth0

The exact interface depends on the platform.

11. Configure a Temporary Linux IPv4 Address

For testing:

sudo ip addr add 10.10.10.10/24 dev <interface>

Bring the interface up:

sudo ip link set <interface> up

Verify:

ip addr show <interface>

For permanent configuration, use the network configuration method appropriate to the installed Linux distribution.

12. Configure NETPLUS-SERVER01

Assign:

IP:
10.10.10.30

Prefix:
/24

Verify:

ip addr

Expected information should include:

inet 10.10.10.30/24

13. Configure NETPLUS-CLIENT01

On Windows, open:

Settings
      ↓
Network & Internet
      ↓
Advanced Network Settings
      ↓
Network Adapter
      ↓
IPv4 Properties

Configure:

IP Address:
10.10.10.20

Subnet Mask:
255.255.255.0

Leave:

Default Gateway

blank for the isolated network in this first exercise.

14. Verify Windows IP Configuration

Run:

ipconfig

For more information:

ipconfig /all

Identify:

Hostname
IPv4 Address
Subnet Mask
Default Gateway
DNS Servers
Physical Address
DHCP Status

15. Verify Linux IP Configuration

Run:

ip addr

Then:

ip route

Identify:

Interface
IPv4 Address
Prefix
Routes

16. Understand the Interface

A system may contain multiple network interfaces.

Example:

Adapter 1
NAT
192.168.x.x

Adapter 2
NETPLUS-LAB
10.10.10.x

Always determine:

Which interface belongs to the network I am troubleshooting?

17. Identify MAC Addresses

On Windows:

getmac

or:

ipconfig /all

On Linux:

ip link

You should identify an address resembling:

08:00:27:12:34:56

This is the interface MAC address.

18. Understand MAC vs IP

At this stage, remember:

MAC Address
     ↓
Layer 2 Identity

while:

IP Address
     ↓
Layer 3 Logical Address

You will investigate this relationship in Lab 05.

19. Test the Local TCP/IP Stack

On every machine:

ping 127.0.0.1

This tests the local IPv4 TCP/IP stack.

Expected:

Reply

or equivalent successful responses.

20. Understand 127.0.0.1

The address:

127.0.0.1

is:

Loopback

It refers to:

This Computer

Conceptually:

Application
    ↓
TCP/IP Stack
    ↓
Loopback
    ↓
Same System

21. Ping NETPLUS-CLIENT01 from NETPLUS-ADMIN

Run:

ping 10.10.10.20

Expected:

64 bytes from 10.10.10.20

Stop:

Ctrl + C

22. Ping NETPLUS-SERVER01

From NETPLUS-ADMIN:

ping 10.10.10.30

Verify connectivity.

23. Test Connectivity from Windows

From NETPLUS-CLIENT01:

ping 10.10.10.10

Then:

ping 10.10.10.30

Successful responses confirm basic IP connectivity.

24. Build the Connectivity Matrix

Record:

Source	Destination	Result
ADMIN	CLIENT01	Pass / Fail
ADMIN	SERVER01	Pass / Fail
CLIENT01	ADMIN	Pass / Fail
CLIENT01	SERVER01	Pass / Fail
SERVER01	ADMIN	Pass / Fail
SERVER01	CLIENT01	Pass / Fail

All should ideally succeed.

25. If Ping Fails

Use the troubleshooting sequence:

Physical / Virtual Adapter
        ↓
Interface Up?
        ↓
IP Address Correct?
        ↓
Subnet Mask Correct?
        ↓
Same Network?
        ↓
Firewall Blocking ICMP?
        ↓
Routing Required?

26. Verify Interface State

On Linux:

ip link

Look for:

UP

If down:

sudo ip link set <interface> up

27. Verify Windows Adapter State

Run:

Get-NetAdapter

Look for:

Status:
Up

Also verify the correct adapter is connected to:

NETPLUS-LAB

28. Understand Same-Subnet Communication

Your systems use:

10.10.10.10/24
10.10.10.20/24
10.10.10.30/24

They belong to:

10.10.10.0/24

Therefore:

ADMIN
   ↓
CLIENT

does not require a router.

The systems communicate locally through Layer 2 networking.

29. View the ARP Table

After pinging another system, run on Windows:

arp -a

On Linux:

ip neigh

You may see:

10.10.10.20
      ↓
MAC Address

This relationship will become important later.

30. Understand ARP at a High Level

When a machine knows:

Destination IP

but needs:

Destination MAC

IPv4 networks commonly use:

ARP

Conceptually:

Who has 10.10.10.20?
       ↓
10.10.10.20 replies:
Here is my MAC address.

31. Check the Routing Table on Windows

Run:

route print

Locate the route for:

10.10.10.0

The connected network should be reachable through the local interface.

32. Check the Linux Routing Table

Run:

ip route

You should see something similar to:

10.10.10.0/24 dev <interface>

This indicates a directly connected route.

33. Understand Directly Connected Networks

Because your interface is:

10.10.10.10/24

the operating system automatically knows:

10.10.10.0/24

is directly reachable.

No manual route is required.

34. Test Hostname Resolution

At this stage, hostname resolution may not work.

For example:

ping NETPLUS-SERVER01

may fail even though:

ping 10.10.10.30

works.

That tells you:

Network Connectivity:
Working

Name Resolution:
Not Configured

This distinction is extremely important in troubleshooting.

35. Understand Connectivity vs DNS

If:

ping 10.10.10.30

works but:

ping NETPLUS-SERVER01

fails, the issue is probably not basic IP connectivity.

Conceptually:

IP Communication
      ✓

Name Resolution
      ✗

You will configure DNS later.

36. Install Wireshark

On the analyst workstation, install Wireshark using your operating system’s approved package method.

On Ubuntu-based systems:

sudo apt update

Then:

sudo apt install wireshark

If prompted about packet-capture permissions, follow your lab environment’s configuration requirements.

37. Verify Wireshark

Launch:

wireshark

Identify the interface connected to:

NETPLUS-LAB

Do not simply choose the first interface.

38. Start Your First Packet Capture

Select the lab interface.

Start capture.

From another terminal:

ping 10.10.10.20

Stop the capture after several packets.

39. Apply an ICMP Filter

In Wireshark:

icmp

You should see:

Echo Request

Echo Reply

Conceptually:

ADMIN
   ↓
ICMP Echo Request
   ↓
CLIENT01

CLIENT01
   ↓
ICMP Echo Reply
   ↓
ADMIN

40. Identify Source and Destination

Select an ICMP packet.

Review:

Ethernet II
Internet Protocol Version 4
Internet Control Message Protocol

Identify:

Source MAC

Destination MAC

Source IP

Destination IP

This is your first practical view of the network layers working together.

41. Capture ARP Traffic

Clear the ARP/neighbor cache only if appropriate for your lab, or generate fresh connectivity to a previously unresolved neighbor.

Apply:

arp

You may observe:

Who has 10.10.10.20?
Tell 10.10.10.10

followed by an ARP reply.

42. Understand What You Just Observed

The communication process was approximately:

Need to Ping 10.10.10.20
        ↓
Is Destination Local?
        ↓
Yes
        ↓
Do I Know Its MAC?
        ↓
No
        ↓
ARP Request
        ↓
ARP Reply
        ↓
ICMP Echo Request
        ↓
ICMP Echo Reply

This workflow will become foundational throughout Network+.

43. Test Traceroute

From Linux:

traceroute 10.10.10.30

If unavailable:

tracepath 10.10.10.30

From Windows:

tracert 10.10.10.30

Because the host is on the same subnet, you should not expect multiple router hops.

44. Understand What Traceroute Measures

Traceroute helps identify:

Source
  ↓
Router 1
  ↓
Router 2
  ↓
Router 3
  ↓
Destination

Later labs will introduce routers so you can observe multi-hop paths.

45. Verify Listening Services

On Windows:

netstat -ano

On Linux:

ss -tulnp

Identify:

Listening Ports

TCP Connections

UDP Sockets

Do not worry about memorizing every service yet.

46. Understand IP, Port, and Application

Networking ultimately allows applications to communicate.

Conceptually:

IP Address
   ↓
Which Device?

Port
   ↓
Which Service?

Protocol
   ↓
How Is Communication Performed?

Example:

10.10.10.30
      ↓
TCP/22
      ↓
SSH

47. Test a Port

If SSH is enabled on NETPLUS-SERVER01, from the administrator workstation:

nc -vz 10.10.10.30 22

or use another approved connectivity-testing utility.

Possible result:

Connection succeeded

This means:

Network Path
+
TCP Port
+
Service Reachability

are available.

48. Understand Ping vs Port Test

A common beginner mistake is assuming:

Ping Works
=
Application Works

This is incorrect.

You may have:

ICMP:
Working

TCP/443:
Blocked

or:

Ping:
Blocked

HTTPS:
Working

Different protocols can have different outcomes.

49. Record the Initial Network Baseline

Document:

Hostnames

IPv4 Addresses

MAC Addresses

Interfaces

Routes

Connectivity

Listening Services

Example:

Host	IP	MAC	OS	Status
NETPLUS-ADMIN	10.10.10.10	`<MAC>`	Linux	Online
NETPLUS-CLIENT01	10.10.10.20	`<MAC>`	Windows	Online
NETPLUS-SERVER01	10.10.10.30	`<MAC>`	Linux	Online

50. Build the Network Diagram

Create:

NETPLUS-LAB
10.10.10.0/24
      |
      +---------------------------+
      |             |             |
      |             |             |
10.10.10.10    10.10.10.20   10.10.10.30
ADMIN           CLIENT01       SERVER01

Your documentation will expand as routers, VLANs, wireless, and network services are introduced.

51. Create the Lab Workspace

On NETPLUS-ADMIN:

mkdir -p ~/NetworkPlus-Labs/LAB01/{Screenshots,Captures,Configs,Notes}

Create:

touch ~/NetworkPlus-Labs/LAB01/Notes/lab01-notes.md

52. Save Your First Packet Capture

Save the Wireshark capture as:

LAB01-ICMP-ARP.pcapng

under:

~/NetworkPlus-Labs/LAB01/Captures/

53. Document Interface Information

On Linux:

ip addr > ~/NetworkPlus-Labs/LAB01/Configs/admin-ip.txt

Then:

ip route > ~/NetworkPlus-Labs/LAB01/Configs/admin-route.txt

On Windows, capture:

ipconfig /all

and save or screenshot the output.

54. Mission Challenge — Fix a Broken Host

Introduce one safe configuration error on NETPLUS-CLIENT01.

For example, change:

10.10.10.20

to:

10.10.20.20

Keep the /24 subnet.

Now test:

ping 10.10.10.30

It should fail under the simple lab design.

Your job is to determine why.

55. Troubleshoot the Broken Host

Follow:

1. Identify Problem

2. Gather Information

3. Establish Theory

4. Test Theory

5. Correct Configuration

6. Verify Connectivity

7. Document

Check:

ipconfig

Compare against the network plan.

You should notice:

Client:
10.10.20.20/24

Server:
10.10.10.30/24

They are no longer in the same /24 network.

56. Correct the Address

Restore:

10.10.10.20
255.255.255.0

Test again:

ping 10.10.10.30

Expected:

Success

57. Mission Challenge — Interface Failure

Another common failure is:

Network Adapter Disabled

Disable the lab adapter temporarily through the guest operating system or virtualization platform.

Observe what happens to:

IP Address

Route

Ping

ARP

Network Status

Then restore the adapter.

58. Mission Challenge — Firewall Behavior

If your OS firewall blocks inbound ICMP:

Ping
   ↓
Failure

does not automatically mean:

Network Is Down

Use multiple tests before concluding connectivity has failed.

For example:

ARP

Port Test

Route

Interface Status

59. Build a Troubleshooting Decision Tree

Use:

Can I reach 127.0.0.1?
        ↓
No → Local TCP/IP issue

Yes
 ↓
Does interface have correct IP?
        ↓
No → Address configuration

Yes
 ↓
Is interface UP?
        ↓
No → Adapter issue

Yes
 ↓
Is destination local?
        ↓
Yes → Check ARP / firewall

No
 ↓
Check gateway / routing

60. Mission Challenge Questions

Answer:

What is the IP address of NETPLUS-ADMIN?
What is the IP address of NETPLUS-CLIENT01?
What is the IP address of NETPLUS-SERVER01?
What subnet mask are you using?
What is the CIDR prefix?
What is the network address?
What is the broadcast address?
Are all three hosts in the same subnet?
What are their MAC addresses?
What command displays Windows IP information?
What command displays Linux IP information?
What command displays the Windows routing table?
What command displays Linux routes?
What is the purpose of 127.0.0.1?
What happens when you ping another local host?
What information does ARP provide?
Which Wireshark filter shows ping traffic?
Which filter displays ARP?
Can IP connectivity work while hostname resolution fails?
Can application connectivity fail even when ping succeeds?
What caused the intentionally broken-host scenario?
How did you fix it?

61. Document Your Findings

Update:

~/NetworkPlus-Labs/LAB01/Notes/lab01-notes.md

Use:

# LAB01 — Network+ Lab Environment

## Environment

Virtualization Platform:

## Network

Network:
10.10.10.0/24

Subnet Mask:
255.255.255.0

## Systems

### NETPLUS-ADMIN

IP:
MAC:
OS:
Interface:

### NETPLUS-CLIENT01

IP:
MAC:
OS:
Interface:

### NETPLUS-SERVER01

IP:
MAC:
OS:
Interface:

## Connectivity

ADMIN → CLIENT:
Pass / Fail

ADMIN → SERVER:
Pass / Fail

CLIENT → SERVER:
Pass / Fail

## Routing

Document directly connected routes.

## ARP

Document observed neighbor mappings.

## Packet Capture

Capture:
LAB01-ICMP-ARP.pcapng

Observed:
- ARP request
- ARP reply
- ICMP echo request
- ICMP echo reply

## Troubleshooting Challenge

Problem:

Root Cause:

Fix:

Verification:

## Final Assessment

Document whether the environment is ready for the remaining Network+ labs.

62. Evidence to Capture

Capture:

01-virtual-network.png

02-netplus-admin.png

03-netplus-client01.png

04-netplus-server01.png

05-admin-ip-config.png

06-client-ipconfig.png

07-server-ip-config.png

08-linux-route.png

09-windows-route.png

10-connectivity-test.png

11-arp-table.png

12-wireshark-interface.png

13-icmp-capture.png

14-arp-capture.png

15-listening-ports.png

16-broken-ip-configuration.png

17-troubleshooting-result.png

18-final-network-topology.png

63. Validation Checklist

Environment

Virtualization platform is ready
NETPLUS-ADMIN created
NETPLUS-CLIENT01 created
NETPLUS-SERVER01 created
Private virtual network created
All systems connected to the lab network

Addressing

NETPLUS-ADMIN configured as 10.10.10.10/24
NETPLUS-CLIENT01 configured as 10.10.10.20/24
NETPLUS-SERVER01 configured as 10.10.10.30/24
Hostnames configured correctly
Interfaces identified
MAC addresses recorded

Connectivity

Loopback tested
ADMIN can reach CLIENT01
ADMIN can reach SERVER01
CLIENT01 can reach SERVER01
Reverse connectivity tested
Connectivity matrix documented

Networking

Windows IP configuration reviewed
Linux IP configuration reviewed
Windows routing table reviewed
Linux routing table reviewed
ARP/neighbor table reviewed
Listening ports reviewed

Packet Analysis

Wireshark installed
Correct capture interface identified
ICMP captured
ARP captured
Source/destination MAC addresses identified
Source/destination IP addresses identified
Packet capture saved

Troubleshooting

Incorrect IP scenario completed
Root cause identified
Configuration corrected
Connectivity verified after correction
Interface-state troubleshooting understood
Firewall behavior considered

Documentation

Network baseline created
Network diagram created
Evidence screenshots captured
Lab notes completed
Environment ready for subsequent labs

64. Mission Review

In this mission, you built the foundation for the entire Network+ practical environment.

You moved from:

Individual Virtual Machines

to:

Virtual Machines
      ↓
Network Interfaces
      ↓
Private Virtual Network
      ↓
IPv4 Addresses
      ↓
Layer 2 Neighbor Discovery
      ↓
IP Connectivity
      ↓
Packet Capture
      ↓
Troubleshooting

You also saw the basic packet-delivery process:

Application
    ↓
IP Destination
    ↓
Local or Remote?
    ↓
ARP if Local
    ↓
Ethernet Frame
    ↓
Destination

The key lesson is:

Before troubleshooting advanced networking technologies, always verify the fundamentals: interface state, addressing, subnet membership, routing, neighbor resolution, and basic connectivity.

Skills Developed

After completing this mission, you should be able to:

build an isolated networking lab
configure virtual network adapters
identify network-interface information
assign static IPv4 addresses
identify IPv4 subnet information
identify MAC addresses
test the loopback interface
verify host-to-host connectivity
read basic routing tables
inspect ARP and neighbor tables
distinguish IP connectivity from name resolution
distinguish ping success from application connectivity
capture ARP and ICMP traffic
use Wireshark at a basic level
apply a structured troubleshooting methodology
document a network baseline

What’s Next?

Lab 02 — TCP/IP and Network Connectivity Fundamentals

Your lab environment is now ready.

In the next mission, you will investigate how devices actually communicate through the TCP/IP stack.

You will work with:

TCP/IP layers
Ethernet
IPv4
TCP
UDP
ICMP
ARP
ports
sockets
TCP three-way handshake
connection states
ping
traceroute
netstat
ss
DNS lookups
Wireshark packet analysis
connectivity troubleshooting

The learning progression becomes:

Lab Environment
      ↓
Interfaces
      ↓
IP Addressing
      ↓
Packets
      ↓
Protocols
      ↓
Ports
      ↓
Connections
      ↓
Applications

➡️ Next: Lab 02 — TCP/IP and Network Connectivity Fundamentals