Practice Free 100-490 Exam Online Questions
Question #11
What is the primary method for recovering or upgrading a Cisco network device system image?
- A . USB storage
- B . FTP
- C . the tftpdnld command
- D . the xmodem command
Correct Answer: C
C
Explanation:
The tftpdnld command in Cisco IOS is specifically designed for recovering or upgrading a system image. Here’s how it’s the most effective method:
Purpose: The tftpdnld command directly initiates a TFTP download of a new system image and stores it in memory. This is ideal for replacing a corrupt image or upgrading to a newer version of Cisco IOS. ROMmon: The tftpdnld command can often be used from ROMmon mode, which is essential when the existing image is unusable.
Efficiency: It streamlines the image transfer process specifically using TFTP, which is commonly used for Cisco IOS images.
Why other options are less ideal:
USB storage: While some newer Cisco devices may allow direct loading of an IOS image from USB, this isn’t universally supported and often requires specific boot commands.
FTP: FTP (File Transfer Protocol) can be used for file transfers, but it’s not as commonly used as TFTP in the context of Cisco IOS image recovery. The tftpdnld command offers a more tailored solution for
this purpose.
the xmodem command: XMODEM is a legacy file transfer protocol that is slower and less reliable than TFTP, especially for larger files like Cisco IOS images.
C
Explanation:
The tftpdnld command in Cisco IOS is specifically designed for recovering or upgrading a system image. Here’s how it’s the most effective method:
Purpose: The tftpdnld command directly initiates a TFTP download of a new system image and stores it in memory. This is ideal for replacing a corrupt image or upgrading to a newer version of Cisco IOS. ROMmon: The tftpdnld command can often be used from ROMmon mode, which is essential when the existing image is unusable.
Efficiency: It streamlines the image transfer process specifically using TFTP, which is commonly used for Cisco IOS images.
Why other options are less ideal:
USB storage: While some newer Cisco devices may allow direct loading of an IOS image from USB, this isn’t universally supported and often requires specific boot commands.
FTP: FTP (File Transfer Protocol) can be used for file transfers, but it’s not as commonly used as TFTP in the context of Cisco IOS image recovery. The tftpdnld command offers a more tailored solution for
this purpose.
the xmodem command: XMODEM is a legacy file transfer protocol that is slower and less reliable than TFTP, especially for larger files like Cisco IOS images.
Question #12
To which value is the configuration register changed to bypass the loading of the startup configuration when performing a password recovery on a Cisco device?
- A . 0x2102
- B . 0x2112
- C . 0x2122
- D . 0x2142
Correct Answer: D
D
Explanation:
The configuration register on Cisco devices controls how the device boots up. By changing the configuration register to 0x2142, you instruct the router to bypass the startup configuration file stored in NVRAM. This is crucial in the password recovery process because the passwords are stored in this configuration file.
Procedure for Password Recovery:
D
Explanation:
The configuration register on Cisco devices controls how the device boots up. By changing the configuration register to 0x2142, you instruct the router to bypass the startup configuration file stored in NVRAM. This is crucial in the password recovery process because the passwords are stored in this configuration file.
Procedure for Password Recovery:
Question #13
Which command displays a list of file systems that are available on Cisco devices?
- A . show memory
- B . show directory
- C . show file system
- D . show version
Correct Answer: C
C
Explanation:
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.
Reference: = File System Commands on Cisco IOS XR Software – Cisco, Working with the Cisco IOS File System, Configuration Files, and Software Images
C
Explanation:
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.
Reference: = File System Commands on Cisco IOS XR Software – Cisco, Working with the Cisco IOS File System, Configuration Files, and Software Images
Question #14
What is the Windows-based program that executes the ping command to test network connectivity?
- A . cmd
- B . Find
- C . Start
- D . ipconfig
Correct Answer: A
A
Explanation:
The cmd program, also known as the Command Prompt, is the primary command-line interface in Windows. It allows you to execute various commands, including the ping command, to perform network testing and troubleshooting.
Here’s how to use ping in the Command Prompt:
Open the Command Prompt: Search for ‘cmd’ in the Windows Start Menu or use the Run dialog (Windows key + R) and type ‘cmd’.
Type the ping command: Enter ping followed by a space and then either the IP address or hostname you want to test. For instance: ping 8.8.8.8 or ping www.google.com.
Press Enter: The Command Prompt will send ping requests and display the results.
Why other options are incorrect:
Find: The Find utility in Windows is used to search for files and folders based on their content or attributes.
Start: The Start Menu in Windows provides access to programs, settings, and power options.
ipconfig: The ipconfig command is used to display network configuration information but doesn’t directly execute the ping command.
Reference: Windows Command Prompt (cmd): https://en.wikipedia.org/wiki/Cmd.exe
Ping command: https://en.wikipedia.org/wiki/Ping_(networking_utility)
A
Explanation:
The cmd program, also known as the Command Prompt, is the primary command-line interface in Windows. It allows you to execute various commands, including the ping command, to perform network testing and troubleshooting.
Here’s how to use ping in the Command Prompt:
Open the Command Prompt: Search for ‘cmd’ in the Windows Start Menu or use the Run dialog (Windows key + R) and type ‘cmd’.
Type the ping command: Enter ping followed by a space and then either the IP address or hostname you want to test. For instance: ping 8.8.8.8 or ping www.google.com.
Press Enter: The Command Prompt will send ping requests and display the results.
Why other options are incorrect:
Find: The Find utility in Windows is used to search for files and folders based on their content or attributes.
Start: The Start Menu in Windows provides access to programs, settings, and power options.
ipconfig: The ipconfig command is used to display network configuration information but doesn’t directly execute the ping command.
Reference: Windows Command Prompt (cmd): https://en.wikipedia.org/wiki/Cmd.exe
Ping command: https://en.wikipedia.org/wiki/Ping_(networking_utility)
Question #15
The colored wires at one end of a cable are in reverse sequence to the colored wires at the other end of the cable.
Which cable does this configuration describe?
- A . rolled
- B . crossover
- C . coaxial
- D . straight-through
Correct Answer: B
B
Explanation:
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.
B
Explanation:
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.
Question #16
Which two sets of pins are looped on an RJ-45 56K loopback plug? (Choose two.)
- A . pins 1 and 4
- B . pins 1 and 7
- C . pins 2 and 5
- D . pins 2 and 7
- E . pins 2 and 8
Correct Answer: AC
AC
Explanation:
An RJ-45 56K loopback plug is used to test the functionality of network ports, particularly for T1/56K lines. The correct loopback wiring for such a plug involves looping pins 1 and 4, as well as pins 2 and 5. This configuration allows the device to send and receive signals on the same wire pairs, effectively testing the transmit and receive paths of the port1.
Reference: = Loopback Tests for T1/56K Lines – Cisco
AC
Explanation:
An RJ-45 56K loopback plug is used to test the functionality of network ports, particularly for T1/56K lines. The correct loopback wiring for such a plug involves looping pins 1 and 4, as well as pins 2 and 5. This configuration allows the device to send and receive signals on the same wire pairs, effectively testing the transmit and receive paths of the port1.
Reference: = Loopback Tests for T1/56K Lines – Cisco
Question #17
Which two features are associated with single-mode fiber-optic cable? (Choose two.)
- A . consists of a single strand of glass fiber
- B . has higher attenuation that multimode fiber
- C . carries a higher bandwidth that multimode fiber
- D . costs less than multimode fiber
- E . operates over less distance than multimode fiber
Correct Answer: AC
AC
Explanation:
The features associated with single-mode fiber-optic cable include:
Consists of a single strand of glass fiber: Single-mode fiber uses a single core (strand) of glass fiber to transmit light signals. This core is thinner than that of multimode fiber, allowing for greater transmission distances.
Carries a higher bandwidth than multimode fiber: Single-mode fiber can carry higher data rates over longer distances compared to multimode fiber. It is commonly used in long-haul communication links and high-speed networks.
Reference: Single-mode vs. Multimode Fiber
Fiber Optic Cable Types
AC
Explanation:
The features associated with single-mode fiber-optic cable include:
Consists of a single strand of glass fiber: Single-mode fiber uses a single core (strand) of glass fiber to transmit light signals. This core is thinner than that of multimode fiber, allowing for greater transmission distances.
Carries a higher bandwidth than multimode fiber: Single-mode fiber can carry higher data rates over longer distances compared to multimode fiber. It is commonly used in long-haul communication links and high-speed networks.
Reference: Single-mode vs. Multimode Fiber
Fiber Optic Cable Types
Question #18
An Ethernet interface is up and the line protocol is down.
What are two possible causes? (Choose two.)
- A . There is a speed or duplex mismatch with the remote device.
- B . There is a Layer 2 mismatch in the encapsulation type.
- C . The Ethernet interface has been manually disabled.
- D . Keepalives are not being received by the local device.
- E . The Ethernet cable might not be attached properly.
Correct Answer: AB
AB
Explanation:
While the initial answers focused on the most common causes, here’s why the other options could also contribute to an interface being stuck in the "up/down" state:
AB
Explanation:
While the initial answers focused on the most common causes, here’s why the other options could also contribute to an interface being stuck in the "up/down" state:
Question #19
Which type of memory is erased on a Cisco device when rebooted?
- A . DRAM
- B . PVDM
- C . flash
- D . NVRAM
Correct Answer: A
A
Explanation:
DRAM, or Dynamic Random-Access Memory, is the type of memory that is erased when a Cisco device is rebooted. DRAM is used to store the running configuration and routing tables of the device. Since DRAM is volatile memory, its contents are lost when the device is powered down or restarted. This is in contrast to non-volatile memory types like flash and NVRAM, which retain their contents even after a reboot1.
Reference: = Types of memory on a Cisco device – Study-CCNA
A
Explanation:
DRAM, or Dynamic Random-Access Memory, is the type of memory that is erased when a Cisco device is rebooted. DRAM is used to store the running configuration and routing tables of the device. Since DRAM is volatile memory, its contents are lost when the device is powered down or restarted. This is in contrast to non-volatile memory types like flash and NVRAM, which retain their contents even after a reboot1.
Reference: = Types of memory on a Cisco device – Study-CCNA
Question #20
Which device is able to be configured as a TFTP server?
- A . CSU/DSU
- B . modem
- C . Cisco router
- D . Cisco Content Engine
Correct Answer: C
C
Explanation:
A Cisco router can be configured to act as a TFTP (Trivial File Transfer Protocol) server. TFTP is a simple protocol used to transfer files without the need for authentication. On a Cisco router, the tftp-server command is used to designate the router as a TFTP server, allowing it to manage file transfers to and from connected devices. This is particularly useful for tasks such as updating the router’s firmware or backing up configuration files. Neither CSU/DSU, modem, nor Cisco Content Engine are typically used as TFTP servers.
Reference: = The ability to configure a Cisco router as a TFTP server is documented in Cisco’s support forums and knowledge base articles
C
Explanation:
A Cisco router can be configured to act as a TFTP (Trivial File Transfer Protocol) server. TFTP is a simple protocol used to transfer files without the need for authentication. On a Cisco router, the tftp-server command is used to designate the router as a TFTP server, allowing it to manage file transfers to and from connected devices. This is particularly useful for tasks such as updating the router’s firmware or backing up configuration files. Neither CSU/DSU, modem, nor Cisco Content Engine are typically used as TFTP servers.
Reference: = The ability to configure a Cisco router as a TFTP server is documented in Cisco’s support forums and knowledge base articles