Cisco Updated 100-490 Exam Questions and Answers by brian

Router

TheAUX (Auxiliary) porton a router is used for dial-in access for CLI (Command Line Interface) management purposes. It is typically connected to a modem and allows an administrator to dial into the router’s CLI for remote management. This port is not used for passing normal network traffic, which differentiates it from other ports like Fast Ethernet or Gigabit Ethernet that handle regular data flow.The AUX port is specifically designed as a backup async port for management access1.

Rollover cables are specifically designed for connecting to the console ports on Cisco routers and switches. Here's why they are the right choice:

• Pinout:Rollover cables have a reversed pinout compared to standard Ethernet cables. This matches the console port's wiring, allowing for configuration access.
• Appearance:Rollover cables are often light blue in color to help distinguish them from standard Ethernet cables.
• USB Adapter:Many modern laptops may not have a direct serial port. In this case, a rollover cable with a USB-to-serial adapter is used.

Why other options are incorrect:

• Straight-through:Used for connecting unlike devices (e.g., switch to computer). They won't have the correct wiring for console connections.
• Fiber:Used for high-speed, long-distance networks. Console ports use a serial-based connection, not fiber optics.
• Crossover:Used to connect similar devices (e.g., switch to switch). The pinout is not the same as what a console port requires.

Electrostatic Discharge (ESD) poses a significant risk to delicate electronic components. Here's why the correct answers are essential tools for ESD protection:

• Antistatic Mat:Provides a grounded surface to work on, dissipating static buildup from your body and the components you're handling.
• ESD Wrist Strap:When connected to a grounding point (often on the antistatic mat), this strap creates an electrical path to safely discharge static electricity from your body.
• Antistatic Bag:These special bags are designed to shield sensitive components from static charge, crucial for storing and transporting electronic parts.

Why other options are incorrect:

• Negative static bag, negative static mat:These terms don't exist in standard ESD protection practices. The focus is on creating a grounded environment to neutralize static charges.
• Latex gloves:While they offer insulation, they can actually generate static electricity, increasing the risk of ESD damage.

NVRAM (Non-Volatile Random Access Memory) is the default storage location for the startup configuration file of a Cisco router or switch.expand_more Here's why:

• Non-Volatility:NVRAM retains its contents even when the device loses power.expand_more This is essential for storing the startup configuration, which contains critical settings like interface configurations, routing protocols, and passwords.
• Read/Write Capability:Unlike ROM, NVRAM allows you to both read and write data. This makes it possible to modify the configuration and save the changes into NVRAM as the startup configuration.

Other Memory Types and Their Functions:

• RAM (Random Access Memory):RAM is volatile memory, meaning it loses its contents when the device is powered off.expand_more It's used to store the running configuration (currently active configuration), routing tables, and other temporary data required for the device's operation.
• ROM (Read-Only Memory):ROM is non-volatile and stores the bootstrap program used to initiate the boot process of the device.expand_more It's not modifiable by the user.expand_more
• Flash:Flash memory is also non-volatile.expand_more It's primarily used to store the Cisco IOS image (operating system) and can also store backup configuration files and other data.