100-490 Cisco Equipment and Related Hardware

Cisco Equipment and Related Hardware (Additional Content) Detailed Explanation

1. LED Indicator Status on Cisco Devices

Understanding the meaning of LED lights on Cisco hardware is important for identifying interface and hardware status at a glance. These indicators can help determine whether a device or port is operational, experiencing errors, or disconnected.

Common LED Color Meanings:

LED Color	Meaning
Green	Port or device is active and functioning correctly
Amber	Warning or fault condition (e.g., link issue, hardware error)
Off	The port or device is not connected or powered down

LED Behavior (Blinking vs. Steady):

• Blinking Green: Port is transmitting or receiving data.

• Steady Green: Port is connected and ready.

• Blinking Amber: Port has encountered errors.

• No Light (Off): Cable is unplugged, device is disabled, or port is shut down.

Exam Tip:

You may see questions like: “What does a blinking amber light on a switch port indicate?” → Answer: Likely a fault or error condition.

2. Modular Expansion Components

Many Cisco devices support modular components that allow for hardware scalability and feature enhancement. Recognizing these parts helps in both device identification and answering configuration-based questions.

Common Modular Components:

• Network Interface Modules (NIM): Allow additional WAN/LAN interface ports to be added.

• Service Modules (SM): Provide capabilities like voice, security, or acceleration.

• StackWise Modules: Used to physically stack multiple switches, allowing them to operate as a single unit.

• SFP/SFP+ Modules: Small pluggable modules that enable fiber or high-speed Ethernet interfaces.

• Flash/SD Cards: Storage expansion modules for IOS files and configurations.

Devices That Support Modules:

Device Type	Common Module Support
ISR Routers	NIMs, SMs, Flash, USB storage
Catalyst Switches	Stack modules, SFPs, redundant power

3. Hardware Support for VLAN and NAT

While VLAN and NAT are software features, it is important to understand which devices typically support and implement them in real-world networks.

VLAN Support:

• Available on: Cisco Catalyst Series Switches

• Use Case: Segregating broadcast domains in Layer 2 networks.

• IOS Configuration: switchport access vlan X, vlan X, name VLAN_HR

NAT Support:

• Available on: Cisco Routers and ASA Firewalls

• Use Case: Translating private IPs to public IPs for internet access.

• IOS Configuration: ip nat inside, ip nat outside, ip nat pool, access-list

VPN Support:

• Available on: Cisco ASA Firewalls, ISR routers with appropriate licenses

• Use Case: Secure communication between remote offices or users.

Exam Relevance:

You may encounter questions such as: “Which Cisco device is best suited to manage internet access for internal users while applying address translation policies?” → Correct answer: ASA Firewall or Cisco Router (with NAT).

4. Console Port Usage and Cabling

The console port is critical for initial configuration and out-of-band management of Cisco devices.

Purpose of Console Port:

• Access the device’s CLI locally when no network access is available.

• Perform password recovery, IOS upgrades, or hardware diagnostics.

Typical Usage Scenario:

1. Connect a computer (with terminal software like PuTTY) to the device using a console cable.

2. Use the console to access the User EXEC mode upon startup.

Common Console Cable Types:

Cable Type	Use Case
RJ-45 to DB-9	Legacy PCs with serial ports
USB-to-RJ45 Console Cable	Newer laptops without serial ports
USB Console (Mini USB)	Found on modern Cisco devices with built-in USB console

Terminal Settings:

• Baud Rate: 9600

• Data Bits: 8

• Stop Bits: 1

• Parity: None

• Flow Control: None