Cisco 100-490 Supporting Cisco Routing & Switching Network Devices (RSTECH) Exam Practice Test

The correct IPv6 address notation follows the format of eight groups of four hexadecimal digits, separated by colons. The address must have exactly eight groups unless it uses the double colon (::) to represent consecutive groups of zero value. The double colon can only appear once in an address to avoid ambiguity.

Option A is incorrect because it includes a subnet mask (/128) which is not part of the actual address notation. Option B is incomplete as it does not contain enough groups and ends with a single colon. Option C has too many groups (nine instead of eight) and is therefore not a valid IPv6 address. Option D is the correct notation with eight groups of four hexadecimal digits, where necessary leading zeros are included.

References :=

IPv6 Address Types, Notation, and Structure Explained1.

IPv6 address formats - IBM2. =========================

A Wide Area Network (WAN) connection typically involves several components that work together to enable data communication over large distances. Two key components of a WAN connection are:

CSU/DSU (Channel Service Unit/Data Service Unit): This device acts as a gateway between the local area network (LAN) and the WAN. It converts the digital signals used in the LAN to the signals used in the WAN, which are often analog12.

Router: A router is used to connect multiple networks together and direct data traffic. In the context of a WAN, routers are responsible for determining the best path for data to travel across the network12.

References := Spiceworks, Cisco

The data link layer of the OSI model, which is Layer 2, defines how data is formatted for transmission and controls access to the physical media. This layer is responsible for the node-to-node delivery of data and handles error detection and correction from the physical layer. It also manages the way data packets are sent over the network, including the framing, addressing, and flow control. The data link layer ensures that messages are delivered to the proper device on a LAN using hardware addresses (MAC addresses) and translates messages from the network layer into bits for the physical layer to transmit

A. Correct. SSH, or Secure Shell, is indeed a protocol that provides a secure remote access connection to network devices. It encrypts the data to ensure secure transmission over insecure networks like the internet1.

C. Correct. Telnet connections are not secure and are terminated when a router reboots. This is because Telnet does not have any mechanism to maintain the connection in case of network interruptions or device reboots1.

B, D, and E are incorrect because: B. SSH uses TCP port 22 by default, not port 23, which is used by Telnet1. D. Telnet does not provide a secure connection; it transmits data in plain text, which can be intercepted easily1. E. SSH is preferred over Telnet for security reasons because it provides encrypted connections and authentication mechanisms, which Telnet does not1.

References :=1: GeeksforGeeks - Difference between SSH and Telnet 2: phoenixNAP - Telnet vs. SSH: How Is SSH Different From Telnet? 3: Guru99 - Telnet vs SSH – Difference Between Them 4: Difference Between - Difference Between Telnet and SSH

A DTE (Data Terminal Equipment) device is an end instrument that converts user information into signals or reconverts received signals. In the context of networking, a router can be considered a DTE device because it is typically at the user end of a user-network interface and serves as a data source or destination. It communicates with the data circuit-terminating equipment (DCE), such as a modem, to send and receive data across the network345.

References := Wikipedia, Techopedia, Network Encyclopedia

The address that facilitates the routing of packets over an IP network is the network address. In the context of IP networking, this refers to the IP address, which is used to identify each host on a network and to determine the best path for data packets to travel from their source to their destination. Routers use IP addresses to make decisions about where to forward packets so that they reach the correct destination. The network layer of the OSI model, where IP operates, is responsible for this routing process123.

The other options listed do not facilitate routing in the same way:

Physical (A) and MAC (D) addresses are used at the data link layer to deliver packets on the same local network.

Transport (B) refers to the transport layer, which is responsible for end-to-end communication and data flow control but does not route packets over an IP network.

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

The line speed of a DS0 in North America is:

C. 64 kbps

DS0, or Digital Signal 0, is a digital signaling standard in telecommunications characterized by its transmission rate of 64 Kbps. It is the basic unit of data in digital networks and is used to transmit a single voice channel or data

To gain console access to a Cisco switch, two types of ports on a laptop can be used: DB-9 and USB. The DB-9 port is a traditional serial port that is often used with a DB-9 to RJ-45 console cable to connect to the switch’s console port1. However, as modern laptops may not have a DB-9 port, a USB to Serial adapter can be used instead, which creates a virtual COM port that can be used to connect to the switch1. The USB port can also be used directly if the switch has a USB console port, which is common on newer Cisco devices. These ports allow for direct physical connection to the switch for configuration and management purposes. References := Access the CLI via PuTTY using a Console Connection on 300 and 500 Series Managed Switches - Cisco, How to connect Switch with console port - Cisco Learning Network

This configuration describes a crossover cable. A crossover cable is used to connect two similar devices directly, such as two computers or two switches, without the need for an intermediate device like a router. The wires at one end of a crossover cable are in reverse sequence to the wires at the other end, which allows the transmit and receive signals to be properly aligned between the two devices. This is different from a straight-through cable, where the wire sequence is the same at both ends1.

For 40 Gigabit Ethernet connectivity, the type of transceiver module used is QSFP+ (Quad Small Form-Factor Pluggable Plus). QSFP+ modules are designed to carry 40-Gigabit Ethernet signals over fiber-optic or copper networking cables. They provide high-density and low-power 40 Gigabit Ethernet connectivity options for data center, high-performance computing networks, enterprise core and distribution layers, and service provider applications. QSFP+ modules are an evolution of the SFP+ (Small Form-Factor Pluggable Plus) modules, offering four times the bandwidth capacity1.

Two standard fiber-optic connectors are Lucent Connectors (LC) and Subscriber Connectors (SC). The Lucent Connector, commonly referred to as LC, was developed by Lucent Technologies and is characterized by its small form factor with a 1.25mm ferrule. It is widely used in high-density applications due to its compact size and square shape1. The Subscriber Connector, or SC, is known for its push-pull latching mechanism and uses a 2.5mm ferrule. It is a square-shaped, duplex connector that has been a dominant fiber optic connector for decades due to its performance and reliability12.

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

The Cisco Nexus 9300 Series switches are a family of high-performance data center switching products. However, only a specific subset of models within this series supports 400-Gbps Ethernet ports.

Based on the information available online, two models from the Cisco Nexus 9300 Series that offer 400-Gbps Ethernet ports are:

Cisco Nexus 9316D-GX: This is a 1RU fixed switch that provides 16 ports of 400 Gbps (QSFP-DD) with a non-blocking switch architecture. It's suitable for aggregation, core, or spine applications.

Cisco Nexus 93600CD-GX: This is also a 1RU fixed switch, but it offers a combination of ports. It includes 28 ports of 100G and 8 ports of 400 Gbps (QSFP-DD) with a non-blocking switch architecture. This model is well-suited for data center Top-of-Rack (ToR), End-of-Row (EoR), and collapsed aggregation and access deployments, particularly when used with Cisco Nexus 2000 Fabric Extenders.

References:

Cisco Nexus 9000 Series 400G Deployment Guide

The tftpdnld command is specifically designed to initiate a TFTP (Trivial File Transfer Protocol) transfer of an image within ROMmon mode on a Cisco device. Here's why it's the correct answer:

ROMmon Functionality: ROMmon (Read-Only Memory Monitor) is a basic operating system mode used when the main Cisco IOS is unavailable. The tftpdnld command works from ROMmon to download a new IOS image.

TFTP Protocol: The tftpdnld command utilizes TFTP, which is a simple and reliable protocol commonly used for transferring Cisco IOS images.

Purpose: The command is used primarily for recovering corrupt images or upgrading to a different IOS version.

Why other options are incorrect:

Xmodem: XMODEM is an older and less reliable file transfer protocol that's less suitable than TFTP for Cisco IOS image transfers.

copy tftp: flash: This command format is used within the Cisco IOS itself, not in ROMmon mode.

copy flash: tftp: This command format would attempt to upload an image from flash memory to a TFTP server, instead of downloading an image.

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.

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.

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.

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.

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 command show file system is used on Cisco devices to display a list of all the file systems available. This command provides information about each file system, including its name, size, free space, and file system type (such as flash or nvram). It’s a useful command for network administrators to manage and navigate through different storage areas on Cisco devices, ensuring they can access and maintain the device’s file structure effectively. References := File System Commands on Cisco IOS XR Software - Cisco, Working with the Cisco IOS File System, Configuration Files, and Software Images