Practice Free 100-490 Supporting Cisco Routing & Switching Network Devices (RSTECH) Exam Questions Answers With Explanation

The image provided shows a networking device connected to a laptop via a console cable. Based on the visual indicators and standard port designs:

C. 3 is a USB 5-pin mini USB Type B port: The port labeled “3” on the laptop is smaller than a standard USB Type A port, which suggests it is a mini USB Type B port, commonly used for connecting to networking devices for console access.

E. 2 is a USB 5-pin mini USB Type B to USB Type A console cable: The cable labeled “2” has one end that fits into the mini USB Type B port on the laptop (as identified in point 1), and the other end, which is not clearly visible in the image, is inferred to be a USB Type A connector that would typically connect to a computer’s USB port.

The Cisco CPAK-100G-SR4 module is designed to support Multimode Fiber (MMF) cable. It is specifically engineered for high-bandwidth 100G optical links and supports link lengths of up to 70 meters over OM3 and 100 meters over OM4 Multimode Fiber with MPO connectors. This module is well-suited for short-range, high-speed data communications and data center applications where Multimode Fiber is typically used due to its ability to handle the large amount of data traffic over relatively short distances. References := Cisco CPAK 100GBASE Modules Data Sheet

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.

A standard UTP (Unshielded Twisted Pair) cable contains 4 pairs of copper wires, which are twisted together to help cancel out electromagnetic interference and support data transmission across various networking and telecommunications applications1. Each pair consists of two individual copper cables twisted around each othe

Microsoft Notepad is the preferred text editor for working with Cisco configuration files and other simple text documents for several reasons:

Plain Text Focus: Notepad is designed specifically for plain text editing. It does not add any formatting, hidden characters, or metadata that could interfere with the configuration file's structure.

Cisco Syntax Compatibility: Cisco configurations rely on specific syntax and spacing. Notepad preserves these elements accurately.

Universality: Notepad is a basic text editor included in all versions of Windows, ensuring accessibility and eliminating the need for additional software.

Why other options are not ideal:

Microsoft Word: Word is a word processor and includes formatting, fonts, and other features that are not compatible with Cisco configuration files. This formatting can corrupt the configuration.

Microsoft Access: Access is a database management system, not suited for text file editing.

Microsoft Excel: Excel is a spreadsheet application and adds its own structure and formatting that conflicts with configuration file formats.

Straight-through cables are the most common type of Ethernet cable. They're used to connect dissimilar devices, such as a laptop to a router or a switch to a router. The internal wiring of the cable connects the transmit pins on one end to the receive pins on the other end, and vice versa.

Crossover cables were historically necessary to connect similar devices (e.g., router to router, or switch to switch). Modern devices often have auto MDI-X capabilities, allowing them to automatically detect and adjust to straight-through or crossover connections as needed.

Rollover cables have a reversed pinout and are primarily used for console access into Cisco routers and switches.

Fiber cables use fiber optic technology for high-speed, long-distance connectivity.

References:

Cisco Networking Academy: Introduction to Networks Course

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.

RJ-45 is the standard connector used for Ethernet networks. Here's why it's the correct answer:

Compatibility: Ethernet ports on both laptops and Cisco switches use RJ-45 connectors. This makes RJ-45 cables ideal for direct connections between these devices.

Appearance: RJ-45 ports are rectangular and slightly larger than typical phone jacks (RJ-11). They have eight metal pins inside.

Why other options are incorrect:

DVI: DVI ports are used for video connections between computers and displays.

RJ-11: RJ-11 ports are primarily associated with analog phone lines and are smaller than RJ-45.

DB-9: DB-9 connectors were traditionally used for serial connections on older computers and peripherals.

The -c option in Xmodem file transfers is used to enable CRC (Cyclic Redundancy Check) for enhanced error checking. Here's why it's the correct answer:

Error Detection: CRC is a more robust error detection mechanism compared to the standard checksum method used in Xmodem. It provides greater reliability in identifying file corruption during the transfer.

Flash Memory: Since flash memory on a Cisco router or switch stores critical data like configuration files or the IOS image, ensuring the integrity of transferred files is crucial.

Why other options are incorrect:

-e, -r, -x: These are not standard Xmodem options for error checking purposes. While some implementations may have custom flags, they are not universally applicable.

Important Note: Xmodem is a legacy protocol that is often replaced by more reliable options like TFTP in modern Cisco devices. However, understanding Xmodem options is still relevant for certain cases or older equipment.

References:

Xmodem overview: https://en.wikipedia.org/wiki/XMODEM

Cyclic Redundancy Check (CRC): https://en.wikipedia.org/wiki/Cyclic_redundancy_check

The command that returns the user to the main configuration prompt from the interface configuration prompt is exit. When you are in interface configuration mode on a Cisco device and you want to return to the global configuration mode, you use the exit command. If you want to go all the way back to privileged EXEC mode, you would use the end command or press Ctrl-Z1.

In the context of IPv4 addresses, a host address is an identifier for a specific device on a network. The addresses 10.1.1.20 and 192.168.10.15 are both within ranges typically reserved for private networks, making them suitable for assignment to host computers within a local network. Address 292.10.3.4 is not a valid IPv4 address because the first octet is beyond the maximum value of 255. Address 255.255.255.255 is reserved for broadcast messages to all hosts on the local network, and 0.0.0.0 is used to denote an unspecified address, often indicating the absence of an IP address123. References := IP address, Network address, and Host address Explained, IP address - Wikipedia, Understanding IP Addresses: How IP Addressing Works | ENP

Cisco NX-OS has added support for Python scripting to help manage user networks. Python is a powerful and versatile scripting language that is widely used for automation tasks, including network management. Cisco NX-OS leverages Python to enable network administrators to write custom scripts and programs that can interact with the network operating system, automate repetitive tasks, and integrate with other systems and APIs. This support for Python scripting is part of Cisco’s commitment to network programmability and automation, allowing for more efficient and flexible network operations12.

The show cdp neighbor command on Cisco devices displays various pieces of information about directly connected neighboring devices that support Cisco Discovery Protocol (CDP). Two key pieces of information displayed by this command are the platform of the neighboring device, which indicates the hardware type, and the device ID, which is typically the hostname of the device1. The command does not display the uptime or the Cisco IOS Software version; these details can be seen with the show cdp neighbor detail command. The IP address is also part of the detailed information and not displayed in the standard show cdp neighbor output1.

The ping command is specifically designed to test network connectivity and reachability. Here's how it works:

Echo Request: The ping command sends an ICMP (Internet Control Message Protocol) Echo Request packet to a specified destination IP address or hostname.

Echo Response: If the target host is reachable, it will respond with an ICMP Echo Reply packet.

Analysis: The ping command measures the round-trip time (RTT) between the source and destination. It also reports statistics like packet loss and response times.

Why other options are incorrect:

echo: In some command-line environments, the echo command is used to display text on the screen and does not relate to network testing.

access: This is a general term and does not refer to a specific command for sending echo requests.

connect: Some tools use the connect command to establish a TCP connection to a remote host, but it doesn't directly utilize ICMP echo packets like the ping command.

References:

ping (Wikipedia): https://en.wikipedia.org/wiki/Ping_(networking_utility)

When you initially log in to a Cisco router, the default operating mode is user EXEC mode. This mode provides a limited set of basic monitoring commands but does not allow for any configuration changes to the router’s settings. To make configuration changes, you must enter privileged EXEC mode (often accessed by the enable command), which offers a wider range of commands that allow for the viewing and modification of the configurationGlobal configuration mode is accessed from privileged EXEC mode to modify the router’s configuration, and ROM monitor mode is a low-level mode used mainly for recovery purposes1.

The show cellular unit network command in Cisco IOS is used to view detailed information about the cellular modem and the network it's connected to. Here's the type of information this command usually displays:

Network Status: Whether the device is registered on the cellular network.

Carrier Information: The name of the cellular network provider.

Technology: The cellular technology in use (e.g., 3G, 4G/LTE).

Signal Strength: Signal strength indicators like RSSI and RSCP.

Cell Site Information: Data about the cell tower or base station the device is connected to.

IP Address: The IP address assigned to the cellular interface.

Why other options are less likely:

show cellular unit radio: Provides information about the radio module itself, such as its state and power levels.

show cellular unit hardware: Focuses on hardware-level information of the cellular unit.

show cellular unit profile: Displays configuration details of the cellular profile used to connect to the network.

References:

Cisco command documentation for different show cellular options: https://www.cisco.com/c/en/us/td/docs/routers/wireless-wan/Cisco-Catalyst-Cellular-Gateways/cisco-cellular-gateways-command-reference-guide/m-show_commands.pdf