Cisco 100-490 Practice Test - Questions Answers

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.

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

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

Theshow cdp neighborcommand 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 theplatformof the neighboring device, which indicates the hardware type, and thedevice 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 theshow cdp neighbor detailcommand.The IP address is also part of the detailed information and not displayed in the standardshow cdp neighboroutput1.

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 version command on Cisco devices provides a variety of system information, including:

Cisco IOS version: The version of the Cisco IOS software running on the device.

Boot image: The location of the IOS image used during startup.

Hardware information: Model, processor type, memory details.

Interfaces: A list of the device's interfaces.

Configuration register: The current value of the configuration register, typically displayed near the end of the output.

Why other options are incorrect:

show flash: Displays the contents of flash memory, but not the configuration register.

show running-config: Displays the currently active configuration, but the configuration register setting is not directly part of the running configuration.

show config-register: This is not a standard Cisco IOS command.

The type of memory used to store Cisco IOS Software permanently isflash memory. Flash memory is non-volatile, meaning it retains its content even after the device is powered down or restarted. It is commonly used in Cisco devices to store one or more Cisco IOS software images, as well as other files such as backup configuration files.This allows the device to reload the operating system after a reboot without the need to retransfer the IOS image

When you initially log in to a Cisco router, the default operating mode isuser 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 enterprivileged EXEC mode(often accessed by theenablecommand), which offers a wider range of commands that allow for the viewing and modification of the configurationGlobal configuration modeis accessed from privileged EXEC mode to modify the router's configuration, andROM monitor modeis a low-level mode used mainly for recovery purposes1.

When deploying Cisco Catalyst 3850 Series switches, there are two modes of operation to choose from: Install mode and Bundle mode. Install mode is the default mode for the switch and uses a package-provisioning file named packages.conf to boot the switch. It allows for a more complete set of features and requires fewer resources upon boot1. Bundle mode, on the other hand, is similar to using traditional monolithic Cisco IOS images to boot the switch. It consumes more memory than Install mode because the packages are extracted from the bundle and copied to the RAM2. Cisco recommends using Install mode for operation due to its efficiency and feature set2.

The commandshow file systemis 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.Reference:=File System Commands on Cisco IOS XR Software - Cisco,Working with the Cisco IOS File System, Configuration Files, and Software Images

The show ip interface brief command provides a concise summary of the status and IP addressing configuration of interfaces on a Cisco router or switch. Here's what it displays:

Interface: The name of the interface (e.g., FastEthernet0/0, GigabitEthernet1/1).

IP Address: The Layer 3 IP address assigned to the interface (if any).

OK? Indicates the IP layer status of the interface (YES if operational, NO if not).

Method: How the IP address was configured (manual or DHCP).

Status: The Layer 1 status of the interface (up or down).

Protocol: The Layer 2 status of the interface (up or down).

Why other options are incorrect:

Layer 2 address: The show ip interface brief command does not directly display Layer 2 (MAC) addresses. You can use the show interface <interface-name> command for that.

Keepalive: Keepalives are used in some routing protocols but are not generally reflected in the output of the show ip interface brief command.

Encapsulation type: Encapsulation information is also not typically included in the show ip interface brief output.

Cisco IOS show ip interface brief command: [invalid URL removed]

Example output of show ip interface brief: https://www.cisco.com/E-Learning/bulk/public/tac/cim/cib/using_cisco_ios_software/cmdrefs/show_ip_interface.