Modules 1 - 4: Switching Concepts, VLANs, and InterVLAN Routing Exam

The "Modules 1 - 4: Switching Concepts, VLANs, and InterVLAN Routing Exam" focuses on foundational networking topics essential for anyone preparing for the Cisco 100-490 RSTECH exam. These modules cover the core principles of how switches operate within a network, the configuration and purpose of VLANs (Virtual Local Area Networks), and how traffic is routed between them using InterVLAN routing. These topics are crucial for understanding network segmentation, traffic management, and efficient troubleshooting—key skills for Cisco technicians supporting small to medium enterprise environments. Mastery of these areas helps candidates succeed in the 100-490 RSTECH certification and build a strong base for more advanced Cisco certifications.

Tech Professionals

13 May 2025

Cisco

Modules 1 - 4: Switching Concepts, VLANs, and InterVLAN Routing Exam

The Cisco 100-490 Supporting Cisco Routing and Switching Network Devices (RSTECH) Certification is a cornerstone for entry-level network technicians, validating skills in installing, configuring, and troubleshooting Cisco routers and switches, critical for roles like field service technicians, network support engineers, and IT support specialists. With 80% of global internet traffic flowing through Cisco infrastructure (Cisco, 2025), the RSTECH certification ensures professionals can maintain robust network environments.

The exam, part of the Cisco Certified Technician (CCT) Routing and Switching track, focuses on foundational topics like switching concepts, VLANs, and interVLAN routing, covered in Modules 1–4 of Cisco’s training curriculum. These modules are tested across Domain 2: Cisco Equipment and Hardware (20%) and Domain 3: Cisco IOS Software Operation (30%), emphasizing LAN connectivity, network segmentation, and routing configurations.

The 100-490 exam, lasting 90 minutes with 55–65 multiple-choice and performance-based questions, requires a passing score of approximately 800 (on a 100–1000 scale). Study4Pass is a premier resource for RSTECH preparation, offering comprehensive study guides, practice exams, and hands-on labs in accessible PDF formats, tailored to the exam syllabus. This article explores Modules 1–4, their significance, relevance to the 100-490 exam, and strategic preparation tips using Study4Pass to achieve certification success.

The RSTECH Role: Supporting Network Devices

The Cisco Certified Technician (CCT) Routing and Switching role involves hands-on support for Cisco network devices, ensuring operational reliability in data centers, enterprises, and service provider environments. Technicians install hardware, configure software, and troubleshoot issues on Cisco routers and switches, supporting networks that handle 5.3 zettabytes of annual IP traffic (Cisco, 2025).

Key Responsibilities:

Hardware Installation: Deploying switches and routers, verifying connections.
Software Configuration: Setting up VLANs, interVLAN routing, and basic security.
Troubleshooting: Diagnosing connectivity issues, such as VLAN misconfigurations or switch port failures.
Maintenance: Upgrading firmware and replacing faulty components. Modules 1–4 (Switching Concepts, VLANs, InterVLAN Routing, and basic troubleshooting) form the foundation for these tasks, equipping technicians to manage LAN connectivity and segmentation. For example, a technician configures VLANs on a Cisco Catalyst switch to isolate departments, improving network efficiency, or enables interVLAN routing to allow communication between segments, saving $50,000 in downtime costs (Gartner, 2024).

Study4Pass aligns with these responsibilities, offering labs that simulate switch configurations and troubleshooting, ensuring RSTECH candidates are job-ready.

The Foundation: Why Modules 1-4 Are Your Starting Point

Modules 1–4 of the Cisco 100-490 RSTECH curriculum provide the bedrock for understanding and supporting Cisco network devices, covering switching concepts, VLANs, interVLAN routing, and implicit troubleshooting skills.

Why They Matter:

Core Networking Knowledge: Switching and VLANs are fundamental to LAN operations, handling 70% of enterprise traffic (IDC, 2025).
Practical Application: Configuring VLANs and interVLAN routing is a daily task for technicians, ensuring network efficiency and security.
Troubleshooting Foundation: Understanding these concepts enables diagnosing common issues, like broadcast storms or routing failures.
Exam Focus: Modules 1–4 account for a significant portion of the 100-490 exam, tested through scenarios like configuring a switch port for a VLAN or verifying interVLAN routing.

Example: A technician uses Module 1 knowledge to set up a switch for Ethernet connectivity, Module 2 to segment traffic with VLANs, and Module 3 to route between VLANs, ensuring a hospital’s network supports critical systems. Study4Pass emphasizes these modules through targeted study materials and labs, helping candidates build a strong foundation for both the exam and real-world tasks.

Module 1: Switching Concepts - How LANs Connect

Module 1:

Switching Concepts introduces the principles of LAN switching, the backbone of local network connectivity.

Key Topics:

Ethernet Fundamentals: Ethernet frames, MAC addresses, and CSMA/CD for media access.
Switch Operation: How switches learn MAC addresses, forward frames, and prevent loops using Spanning Tree Protocol (STP).
Switch Ports: Configuring access and trunk ports for device connectivity.
Collision and Broadcast Domains: Reducing collisions through switching and managing broadcasts.

Function: Switches connect devices within a LAN, forwarding frames based on MAC addresses, unlike routers, which use IP addresses.

Example: A Cisco Catalyst 2960 switch learns a PC’s MAC address and forwards frames to a server, enabling file sharing in an office.

RSTECH Relevance: Technicians configure switch ports and verify connectivity, ensuring devices communicate efficiently.

Challenges: Misconfigured ports or disabled STP can cause network loops, requiring Module 1 knowledge to resolve. Study4Pass labs simulate switch setups, guiding candidates through MAC table analysis and port configurations, aligning with exam scenarios like enabling a switch port for a new device.

Module 2: VLANs - Segmenting Your Network Smarter

Module 2:

VLANs (Virtual Local Area Networks) covers network segmentation, enhancing security, performance, and manageability.

Key Topics:

VLAN Definition: Logical groups of devices on the same physical switch, isolated by VLAN IDs (e.g., VLAN 10 for HR, VLAN 20 for IT).
VLAN Benefits: Reduces broadcast traffic, improves security by isolating sensitive data, and simplifies management.
VLAN Configuration: Assigning ports to VLANs (access ports) and configuring trunk ports to carry multiple VLANs.
VLAN Tagging: Using IEEE 802.1Q to tag frames with VLAN IDs on trunk links.

Function: VLANs segment traffic, preventing HR devices from accessing IT servers unless explicitly allowed.

Example: A technician configures VLAN 30 for guest Wi-Fi on a Cisco switch, isolating it from VLAN 10 (corporate), preventing unauthorized access and saving $100,000 in potential breach costs (IBM Security, 2024).

RSTECH Relevance: Technicians create and manage VLANs to support organizational policies and troubleshoot segmentation issues. Study4Pass labs simulate VLAN assignments, such as configuring a switch port for VLAN 20, ensuring candidates master segmentation for the exam and field tasks.

Module 3: InterVLAN Routing - Connecting the Segments

Module 3:

InterVLAN Routing enables communication between VLANs, critical for integrated network operations.

Key Topics:

InterVLAN Routing Methods: Router-on-a-Stick (using a router with a single interface and subinterfaces) and Layer 3 Switching (using a multilayer switch).
Configuration: Setting up subinterfaces on a router (e.g., Gi0/0.10 for VLAN 10) or enabling IP routing on a switch.
Encapsulation: Using 802.1Q tagging to identify VLAN traffic
Routing Protocols: Basic static routes or dynamic protocols for VLAN connectivity.

Function: InterVLAN routing allows devices in different VLANs to communicate, such as an HR PC accessing an IT server.

Example: A technician configures a Cisco 2911 router with subinterfaces Gi0/0.10 (VLAN 10) and Gi0/0.20 (VLAN 20), enabling interdepartmental file sharing, improving collaboration.

RSTECH Relevance: Technicians set up and troubleshoot interVLAN routing to ensure seamless connectivity across segments.

Challenges: Misconfigured subinterfaces or missing trunk links can block communication, requiring Module 3 expertise. Study4Pass labs simulate router-on-a-stick setups, guiding candidates through subinterface configurations and routing verification, preparing them for exam tasks.

Module 4 (Implicit): Application and Basic Troubleshooting

While not explicitly labeled as Module 4, the RSTECH curriculum integrates application and basic troubleshooting across Modules 1–3, focusing on practical skills for supporting Cisco devices.

Key Topics:

Switch Configuration: Verifying port status, VLAN assignments, and MAC tables using commands like show vlan brief or show mac address-table.
Troubleshooting Tools: Commands like show running-config, show ip interface brief, and ping to diagnose issues.
Common Issues: Port misconfigurations, VLAN mismatches, or interVLAN routing failures.
Best Practices: Documenting changes, verifying connectivity, and escalating unresolved issues.

Function: Troubleshooting ensures network reliability, such as fixing a VLAN 10 device unable to reach VLAN 20 due to a missing subinterface.

Example: A technician uses show vlan brief to confirm a port is in the wrong VLAN, reassigns it, and restores connectivity for a retail POS system, preventing $10,000 in lost sales.

RSTECH Relevance: Technicians rely on troubleshooting skills to maintain uptime and support critical operations. Study4Pass labs provide hands-on troubleshooting scenarios, such as diagnosing a trunk link failure, ensuring candidates are exam- and job-ready.

Types of Questions You'll See (Relating to Modules 1-4)

The 100-490 RSTECH exam tests Modules 1–4 through various question formats, assessing theoretical knowledge and practical skills.

Multiple-Choice Questions:

Switching Concepts: “What is the purpose of the MAC address table in a switch?” (Answer: To map MAC addresses to ports for frame forwarding).
VLANs: “Which command displays VLAN configurations on a Cisco switch?” (Answer: show vlan brief).
InterVLAN Routing: “What is required for router-on-a-stick interVLAN routing?” (Answer: Subinterfaces with 802.1Q encapsulation).

Performance-Based Questions:

Configure a switch port as an access port for VLAN 10. Candidates enter commands like interface fa0/1, switchport mode access, switchport access vlan 10.
Set up a router subinterface for VLAN 20. Commands include interface gi0/0.20, encapsulation dot1Q 20, ip address 192.168.20.1 255.255.255.0.
Troubleshoot a VLAN mismatch using show vlan brief.

Scenario-Based Questions:

Diagnose why VLAN 10 devices cannot reach VLAN 30, identifying a missing trunk link or routing configuration. Study4Pass practice exams include these question types, with labs simulating Cisco IOS commands, ensuring candidates are prepared for all formats.

Mastering Modules 1-4 for RSTECH Success

Scenario-Based Application

In a real-world scenario, a small business reports that its accounting department (VLAN 10) cannot access the sales server (VLAN 20), disrupting operations. The solution involves applying Modules 1–4:

Module 1—verify switch port connectivity using show mac address-table.
Module 2—check VLAN assignments with show vlan brief, confirming ports are in correct VLANs.
Module 3—configure interVLAN routing on a Cisco 2911 router, adding subinterfaces (e.g., Gi0/0.10, Gi0/0.20) with encapsulation dot1Q and IP addresses.
Module 4—troubleshoot using ping and show ip interface brief to ensure routing is active.

The technician discovers a missing trunk link, configures it with switchport mode trunk, and restores connectivity, saving $20,000 in downtime. For the 100-490 exam, a related question might ask, “Which command configures a VLAN 10 access port?” (Answer: switchport access vlan 10). Study4Pass labs replicate this scenario, guiding candidates through switch and router configurations, VLAN setups, and troubleshooting, aligning with performance-based tasks.

Troubleshooting Common Issues

RSTECH technicians frequently address issues related to Modules 1–4, requiring 100-490 expertise.

Issue 1: Device Cannot Connect—caused by a disabled switch port; the solution involves enabling it with no shutdown.
Issue 2: VLAN Misconfiguration—devices in the wrong VLAN; the solution uses show vlan brief to reassign ports.
Issue 3: InterVLAN Routing Failure—due to missing subinterfaces; the solution configures them with encapsulation dot1Q.

Example: A technician uses show running-config to identify a VLAN 30 port assigned to VLAN 1, corrects it, and enables interVLAN routing, restoring a school’s network. Study4Pass provides performance-based labs to practice these troubleshooting tasks, preparing candidates for 100-490 scenarios.

Best Practices for Exam Preparation

To excel in Modules 1–4 questions, candidates should follow best practices.

Concept Mastery: Study switching, VLANs, and interVLAN routing using Study4Pass guides, focusing on commands like show vlan brief and encapsulation dot1Q.
Practical Skills: Practice configuring switches and routers in labs, simulating Cisco IOS environments.
Scenario Practice: Solve real-world scenarios, such as troubleshooting VLAN mismatches, to build confidence.
Time Management: Complete timed practice exams to simulate the 90-minute 100-490 test.

For instance, a candidate uses Study4Pass to configure interVLAN routing, achieving 92% accuracy in practice tests. Study4Pass reinforces these practices through guided labs, practice exams, and scenario-based questions, ensuring exam and career readiness.

Bottom Line: The Bedrock of RSTECH Knowledge

The Cisco 100-490 RSTECH certification equips technicians with essential skills, with Modules 1–4: Switching Concepts, VLANs, InterVLAN Routing, and Troubleshooting forming the bedrock of knowledge for supporting Cisco network devices. These modules enable candidates to configure LAN connectivity, segment networks, route between VLANs, and diagnose issues, ensuring reliable operations in dynamic environments.

Study4Pass is the ultimate resource for 100-490 preparation, offering study guides, practice exams, and hands-on labs that replicate Cisco configurations and scenarios. Its lab-focused approach and scenario-based questions ensure candidates can configure, troubleshoot, and verify network setups confidently. With Study4Pass, aspiring technicians can ace the exam and launch rewarding careers, with salaries averaging $50,000–$75,000 annually for entry-level roles (Glassdoor, 2025).

Exam Tips: Memorize key commands (show vlan brief, switchport mode trunk), practice switch and router setups in Study4Pass labs, solve scenarios for VLAN and routing issues, review related concepts (MAC tables, STP), and complete timed 65-question practice tests to manage the 90-minute exam efficiently.