1.
For which type of connection should a straight-through cable be used?
Correct Answer
C. C. switch to router
Explanation
To specify when we use crossover cable or straight-through cable, we should remember:
Group 1: Router, Host, Server
Group 2: Hub, Switch
One device in group 1 + One device in group 2: use straight-through cable
Two devices in the same group: use crossover cable
In this case we can use straight-through cable to connect a switch to a router -> C is correct.
2.
Which type of cable is used to connect the COM port of a host to the COM port of a router or switch?
Correct Answer
C. C. rolled
Explanation
Explanation
The correct question should be “Which type of cable is used to connect the COM port of a host to the CONSOLE port of a router or switch?” and the correct answer is rollover cable. But we can’t plug this rollover cable directly into our host because it will not work. We often use a RJ45 to DB9 Female cable converter as shown below:
3.
What is the first 24 bits in a MAC address called?
Correct Answer
C. C. OUI
Explanation
Organizational Unique Identifier (OUI) is the first 24 bits of a MAC address for a network device, which indicates the specific vendor for that device as assigned by the Institute of Electrical and Electronics Engineers, Incorporated (IEEE). This identifier uniquely identifies a vendor, manufacturer, or an organization.
4.
In an Ethernet network, under what two scenarios can devices transmit? (Choose two)
Correct Answer(s)
C. C. when they detect no other devices are sending
D. D. when the medium is idle
Explanation
Ethernet network is a shared environment so all devices have the right to access to the medium. If more than one device transmits simultaneously, the signals collide and can not reach the destination.
If a device detects another device is sending, it will wait for a specified amount of time before attempting to transmit.
When there is no traffic detected, a device will transmit its message. While this transmission is occurring, the device continues to listen for traffic or collisions on the LAN. After the message is sent, the device returns to its default listening mode.
So we can see C and D are the correct answers. But in fact “answer C – when they detect no other devices are sending” and “when the medium is idle” are nearly the same.
5.
Which two benefits are provided by using a hierarchical addressing network addressing scheme? (Choose two)
Correct Answer(s)
A. A. reduces routing table entries
E. E. ease of management and troubleshooting
Explanation
A hierarchical addressing network addressing scheme provides two benefits. Firstly, it reduces routing table entries, which means that the routing tables in network devices will be smaller and more efficient. This helps in improving the overall performance and scalability of the network. Secondly, it offers ease of management and troubleshooting. With a hierarchical addressing scheme, network administrators can easily organize and manage the network by dividing it into smaller subnets. This makes it simpler to troubleshoot network issues and locate the source of problems.
6.
When a host transmits data across a network to another host, which process does the data go through?
Correct Answer
C. C. encapsulation
Explanation
When a host transmits data across a network to another host, the data goes through the process of encapsulation. Encapsulation involves wrapping the data with additional information, such as headers and trailers, to create a packet. This packet is then transmitted over the network. Encapsulation helps ensure that the data can be properly routed and delivered to the intended recipient by providing necessary information for the network devices to process and handle the data effectively.
7.
Which two Ethernet fiber-optic modes support distances of greater than 550 meters?
Correct Answer(s)
C. C. 1000BASE-LX
E. E. 1000BASE-ZX
Explanation
Below lists the cabling standards mentioned above
Standard Cabling Maximum length
1000BASE-CX Twinaxial cabling 25 meters
100BASE-FX Two strands, multimode 400 m
1000BASE-LX Long-wavelength laser, MM or
SM fiber 10 km (SM)
3 km (MM)
1000BASE-SX Short-wavelength laser, MM fiber 220 m with 62.5-micron fiber; 550 m
with 50-micron fiber
1000BASE-ZX Extended wavelength, SM fiber 100 km
8.
Refer to the exhibit. What type of connection would be supported by the cable diagram shown?
Correct Answer
B. B. PC to switch
Explanation
From the “Pin” and “Color” in the exhibit we know that this is a straight-through cable so it can be used to connect PC to switch.
9.
Which two topologies are using the correct type of twisted-pair cables? (Choose two)
Correct Answer(s)
D.
E.
Explanation
The two topologies that use the correct type of twisted-pair cables are Ethernet and Token Ring. Ethernet is a widely used local area network (LAN) technology that uses twisted-pair cables to transmit data. Token Ring is another LAN technology that also uses twisted-pair cables for data transmission. Both of these topologies rely on the use of twisted-pair cables to ensure reliable and efficient data transfer within the network.
10.
Refer to the exhibit. What type of connection would be supported by the cable diagram shown?
Correct Answer
A. A. PC to router
Explanation
Explanation
This is a crossover cable so it can be used to connect PC and router.
11.
What are some of the advantages of using a router to segment the network? (Choose two)
Correct Answer(s)
A. A. Filtering can occur based on Layer 3 information.
D. D. Broadcasts are not forwarded across the router.
Explanation
A router can segment a network by creating separate broadcast domains, which helps to reduce network congestion and improve performance. By doing so, it can filter network traffic based on Layer 3 information such as IP addresses, which allows for more granular control over network traffic and enhances network security. Additionally, routers do not forward broadcast traffic across different network segments, preventing unnecessary network traffic and improving overall network efficiency.
12.
Which of the following statements describe the network shown in the graphic? (Choose two)
Correct Answer(s)
A. A. There are two broadcast domains in the network.
F. F. There are seven collision domains in the network.
Explanation
Only router can break up broadcast domains so in the exhibit there are 2 broadcast domains: from e0 interface to the left is a broadcast domain and from e1 interface to the right is another broadcast domain -> A is correct.
Both router and switch can break up collision domains so there is only 1 collision domain on the left of the router (because hub doesn’t break up collision domain) and there are 6 collision domains on the right of the router (1 collision domain from e1 interface to the switch + 5 collision domains for 5 PCs in Production) -> F is correct.
13.
Refer to the exhibit. The two connected ports on the switch are not turning orange or green. What would be the most effective steps to troubleshoot this physical layer problem? (Choose three)
Correct Answer(s)
B. B. Ensure that cables A and B are straight-through cables.
D. D. Ensure the switch has power.
E. E. Reboot all of the devices.
Explanation
The ports on the switch are not up indicating it is a layer 1 (physical) problem so we should check cable type, power and how they are plugged in.
14.
For what two purposes does the Ethernet protocol use physical addresses? (Choose two)
Correct Answer(s)
A. A. to uniquely identify devices at Layer 2
E. E. to allow communication between different devices on the same network
Explanation
Physical addresses or MAC addresses are used to identify devices at layer 2 -> A is correct.
MAC addresses are only used to communicate on the same network. To communicate on different network we have to use Layer 3 addresses (IP addresses) -> B is not correct; E is correct.
Layer 2 frame and Layer 3 packet can be recognized via headers. Layer 3 packet also contains physical address -> C is not correct.
On Ethernet, each frame has the same priority to transmit by default -> D is not correct.
All devices need a physical address to identify itself. If not, they can not communicate -> F is not correct.
15.
Refer to the exhibit. Two buildings on the San Jose campus of a small company must be connected to use Ethernet with a bandwidth of at least 100 Mbps. The company is concerned about possible problems from voltage potential difference between the two buildings. Which media type should be used for the connection?
Correct Answer
D. D. Fiber optic cable
Explanation
Because the company has problem about voltage potential difference between the two buildings so they should connect via fiber optic cable which uses light pulses to transmit information instead of using electronic pulses.
16.
Which command can be used from a PC to verify the connectivity between host that connect through path?
Correct Answer
A. A. tracert address
Explanation
To check the connectivity between a host and a destination (through some networks) we can use both “tracert” and “ping” commands. But the difference between these 2 commands is the “tracert” command can display a list of near-side router interfaces in the path between the source and the destination. Therefore the best answer in this case is A – tracert address.
Note: “traceroute” command has the same function of the “tracert” command but it is used on Cisco routers only, not on a PC.
17.
Refer to the exhibit. A network engineer is troubleshooting an internet connectivity problem on the computer. What causing the problem?
Correct Answer
C. C. incorrect IP address
Explanation
The IP address of the PC (192.168.11.2/24) is not on the same network with its gateway 192.168.1.1 -> C is correct.
18.
How many broadcast domains are shown in the graphic assuming only the default vlan is configured on the switches?
Correct Answer
A. A. one
Explanation
Only router can break up broadcast domains but in this exhibit no router is used so there is only 1 broadcast domain.
For your information, there are 7 collision domains in this exhibit (6 collision domains between hubs & switches + 1 collision between the two switches).
19.
Refer to the exhibit.
PC> tracert 10.16.176.23
Tracing route to 10.16.176.23 over a maximum of 30 hops
1 31 ms 31 ms 32ms 172.16.182.1
2 62 ms 62 ms 62 ms 192.1681.6
3 93 ms 92 ms 34 ms 192.168.1.10
4 125 ms 110ms 125ms 10.16.176.23
Trace complete.
Host A has tested connectivity to a remote network. What is the default gateway for host A?
Correct Answer
A. A. 172.16.182.1
Explanation
It will list all the routers (from nearest to farthest) it passes through until it reaches its destination so the first hop is its nearest IP. If we ping from a PC, it is also the default gateway for that PC -> A is correct.
20.
What functions do routers perform in a network? (Choose two)
Correct Answer(s)
A. A. packet switching
C. C. path selection
Explanation
Routers perform two main functions in a network. The first function is packet switching, which involves receiving packets from one network and forwarding them to another network based on their destination IP addresses. This allows for efficient and reliable data transmission between different networks. The second function is path selection, where routers determine the best path for packets to travel through the network. This involves analyzing factors such as network congestion, link quality, and routing protocols to ensure that packets are delivered in the most efficient and reliable manner.
21.
How does using the service password encryption command on a router provide additional security?
Correct Answer
B. B. by encrypting passwords in the plain text configuration file
Explanation
By using this command, all the (current and future) passwords are encrypted. This command is primarily useful for keeping unauthorized individuals from viewing your password in your configuration file.
22.
Refer to the diagram. What is the largest configuration file that can be stored on this router?
R# show version
Cisco IOS Software. 1841 Software (C1841-IPBASE-M}, Version 12.4(1a), RELEASE SOFTWARE (fc2)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986*2005 by Cisco Systems, Inc.
Compiled Fri 27-May-0512:32 by hqluong
ROM: System Bootstrap. Version 12.3(8r)T8, RELEASE SOFTWARE (fc1)
N-East uptime is 5 days, 49 minutes
System returned to ROM by reload at 15:17:00 UTC Thu Jun 8 2006
System image file is “flash:c1841-ipbase-mz.124-1a.bin”
Cisco 1841 (revision 5.0) with 114688K/16384K bytes of memory.
Processor board ID FTX0932W21Y
2 FastEthernet interfaces
2 Low-speed serial(sync/async) interfaces
DRAM configuration is 64 bits wide with parity disabled.
191K bytes of NVRAM.
31360K bytes of ATA CompactFlash (Read/Write)
Configuration register Is 0×2102
R#
Correct Answer
A. A. 191K bytes
Explanation
Non-volatile RAM (NVRAM) holds the router’s startup configuration file. NVRAM contents are not lost when the router is powered down or reloaded.
23.
Which command shows system hardware and software version information?
Correct Answer
E. E. show version
Explanation
The correct answer is E. show version. This command is used to display the hardware and software version information of a system. It provides details such as the operating system version, firmware version, hardware model, and other relevant information. By using this command, users can quickly gather information about the system's configuration and ensure compatibility with software updates or troubleshooting purposes.
24.
Refer to the exhibit. If number 2 is selected from the setup script, what happens when the user runs setup from a privileged prompt?
[0] Go to the IOS command prompt without saving this config.
[1] Return back to the setup without saving this config.
[2] Save this configuration to nvram and exit.
Enter your selection [2]:
Correct Answer
A. A. Setup is additive and any changes will be added to the config script.
Explanation
When the user selects option 2 and runs setup from a privileged prompt, the setup process will save the configuration to nvram and exit. This means that any changes made during the setup process will be added to the existing configuration script. This option indicates that the setup is additive and does not start the configuration over from scratch. Therefore, the correct answer is A.
25.
Which command shows your active Telnet connections?
Correct Answer
A. A. show sessions
Explanation
The command "show sessions" is used to display the active Telnet connections. This command provides information about the current Telnet sessions that are established on the device. By using this command, users can see details such as the source and destination IP addresses, session duration, and other relevant information about the active Telnet connections.
26.
Which command can you use to determine the cisco ios feature set on a cisco router?
Correct Answer
A. A. show version
Explanation
The correct answer is A. show version.
The "show version" command can be used to determine the Cisco IOS feature set on a Cisco router. This command provides detailed information about the router's hardware and software, including the IOS version, feature set, and license information. By using the "show version" command, network administrators can quickly verify the installed IOS feature set and ensure that the router has the necessary features and capabilities for their network requirements.
27.
A system administrator types the command to change the hostname of a router. Where on the Cisco IFS is that change stored?
Correct Answer
B. B. RAM
Explanation
The change is only reflected in the running-config on RAM. It can be lost if we reset the router without saving it.
Note: Cisco IFS means “Cisco IOS File System”
28.
Before installing a new, upgraded version of the IOS, what should be checked on the router, and which command should be used to gather this information? (Choose two)
Correct Answer(s)
B. B. the amount of available flash and RAM memory
D. D. show version
Explanation
When upgrading new version of the IOS we need to copy the IOS to the Flash so first we have to check if the Flash has enough memory or not. Also running the new IOS may require more RAM than the older one so we should check the available RAM too. We can check both with the “show version” command.
29.
Refer to the exhibit. A network administrator configures a new router and enters the copy startup-config running-config on the router. The network administrator powers down the router and sets it up at a remote location. When the router starts, it enter the system configuration dialog as shown. What is the cause of the problem?
— System Configuration Dialog —
Would you like to enter the initial configuration dialog? [yes/no]: % Please answer yes’ or ‘no’.
Would you like to enter the initial configuration dialog? [yes/ho]: n
Would you like to terminate autoinstall? [yes]:
Press RETURN to get started!
Correct Answer
A. A. The network administrator failed to save the configuration.
Explanation
The “System Configuration Dialog” appears only when no startup configuration file is found. The network administrator has made a mistake because the command “copy startup-config running-config” will copy the startup config (which is empty) over the running config (which is configured by the administrator). So everything configured was deleted.
Note: We can tell the router to ignore the start-up configuration on the next reload by setting the register to 0×2142. This will make the “System Configuration Dialog” appear at the next reload.
30.
Refer to the exhibit. What can be determined about the router from the console output?
Correct Answer
A. A. No configuration file was found in NVRAM.
Explanation
When no startup configuration file is found in NVRAM, the System Configuration Dialog will appear to ask if we want to enter the initial configuration dialog or not.
31.
When you are logged into a switch, which prompt indicates that you are in privileged mode?
Correct Answer
E. E. #
Explanation
The “#” (like Switch#) indicates you are in privileged mode while the “>” indicates you are in user mode.
Note: The “#” sign in “Switch(config)#” indicates this is only accessible at privileged EXEC mode. The “(config)#” part indicates we are in configuration mode.
Below lists popular modes in Cisco switch/router:
Router> User EXEC mode
Router# Privileged EXEC mode
Router(config)# Configuration mode
Router(config-if)# Interface level (within configuration mode)
Router(config-router)# Routing engine level (within configuration mode)
Router(config-line)# Line level (vty, tty, async) within configuration mode
32.
Which command is used to copy the configuration from RAM into NVRAM?
Correct Answer
A. A. copy running-config startup-config
Explanation
The running-config is saved in RAM while the startup-config is saved in NVRAM. So in order to copy the configuration from RAM into NVRAM we use the command “copy running-config startup-config” (syntax: copy ).
33.
Which command is used to load a configuration from a TFTP server and merge the configuration into RAM?
Correct Answer
B. B. copy TFTP: running-config
Explanation
The syntax of the copy command is “copy ” so to copy a configuration from a TFTP server into RAM we use the command “copy TFTP: running-config”
34.
There are no boot system commands in a router configuration in NVRAM. What is the fallback sequence that router will use to find an IOS during reload?
Correct Answer
A. A. Flash, TFTP server, ROM
Explanation
When you turn the router on, it runs through the following boot process.
The Power-On Self Test (POST) checks the router’s hardware. When the POST completes successfully, the System OK LED indicator comes on.
The router checks the configuration register to identify where to load the IOS image from. A setting of 0×2102 means that the router will use information in the startup-config file to locate the IOS image. If the startup-config file is missing or does not specify a location, it will check the following locations for the IOS image:
1. Flash (the default location)
2. TFTP server
3. ROM (used if no other source is found)
The router loads the configuration file into RAM (which configures the router). The router can load a configuration file from:
+ NVRAM (startup-configuration file)
+ TFTP server
If a configuration file is not found, the router starts in setup mode.
35.
A Cisco router is booting and has just completed the POST process.It is now ready to find and load an IOS image. What function does the router perform next?
Correct Answer
A. A. It checks the configuration register
Explanation
After completing the POST process, a Cisco router will perform the next function by checking the configuration register. The configuration register is a 16-bit value that determines how the router will boot up. It specifies various options such as boot source, console speed, and whether to ignore the startup configuration. By checking the configuration register, the router can determine the boot settings and proceed accordingly.
36.
Refer to the partial command output shown. Which two statements are correct regarding the router hardware? (Choose two)
system image file is “flash:c2600-do3s-mz.120-5.T1″
Cisco 2621 (MPC860) processor (revision 0×600) with 53248K/12288K bytes of memory
Processor board ID JAD05280307 (3536592999)
M860 processor: part number 0, mask 49
Bridging software.
X.25 software, version 3.0.0.
2 FastEthernet/IEEE 802.3 interface(s)
2 Serial(sync/async) network interface(s)
2 Low-speed serial(sync/async) network interface(s)
16 terminal line(s)
32K bytes of non-volatile configuration memory.
16384K bytes of processor board system flash (Read/Write)
Correct Answer(s)
C. C. Total RAM size is 65536 KB (64 MB)
E. E. Flash size is 16384 KB (16 MB)
Explanation
The line “Cisco 2621 (MPC860) processor (revision 0×600) with 53248K/12288K bytes of memory” tells how much RAM in your router. The first parameter (53248) specifies how much Dynamic RAM (DRAM) in your router while the second parameter (12288K) indicates how much DRAM is being used for Packet memory (used by incoming and outgoing packets) in your router. Therefore you have to add both numbers to find the amount of DRAM available on your router -> C is correct.
Note: Cisco 4000, 4500, 4700, and 7500 routers have separate DRAM and Packet memory, so you only need to look at the first number to find out the DRAM in that router.
The flash size is straightforward from the line “16384K bytes of processor board system flash (Read/Write)” -> E is correct.
37.
Which router IOS commands can be used to troubleshoot LAN connectivity problems? (Choose three)
Correct Answer(s)
A. A. ping
D. D. show ip route
F. F. show interfaces
Explanation
The ping command can be used to test if the local device can reach a specific destination -> A is correct.
“tracert” is not a valid command in Cisco IOS commands, the correct command should be “traceroute” -> B is not correct.
The ipconfig command is not a valid command in Cisco IOS too -> C is not correct.
The “show ip route” command can be used to view the routing table of the router. It is a very useful command to find out many connectivity problems (like directly connected networks, learned network via routing protocols…) -> D is correct.
“winipcfg” is an old tool in Windows 95/98 to view IP settings of the installed network interfaces. But it is not a valid command in Cisco IOS commands -> E is not correct.
The “show interfaces” command is used to check all the interfaces on the local device only. It has very limited information to trouble LAN connectivity problem but it is the most reasonable to choose -> F is acceptable.
38.
Which two locations can be configured as a source for the IOS image in the boot system command? (Choose two)
Correct Answer(s)
C. C. flash memory
E. E. TFTP server
Explanation
The following locations can be configured as a source for the IOS image:
+ Flash (the default location)
+ TFTP server
+ ROM (used if no other source is found)
39.
Refer to the exhibit. Why is flash memory erased prior to upgrading the IOS image from the TFTP server?
Router# copy tftp flash
Address or name of remote host []? 192.168.2.167
Source filename []? c1600-k8sy-mz.123-16a.bin
Destination filename [c1600-k8sy-mz.123-16a.bin]?
Accessing tftp://192.168.2.167/ c1600-k8sy-mz.l23-16a.bin…
Erasing flash before copying? [confirm]
Erasing the flash filesystem will remove all files! continue? [confirm]
Erasing device
Eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee
Eeeeeeeeeeeeeeeeeeeeeeeeeeeeeee …erased
Erase of flash: complete
Loading c1600-k8sy-mz.l23-16a.bin from 192.168.2.167 (via Ethernet0):
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
[OK - 6888962/13777920 bytes]
verifying checksum… OK (0x7BF3)
6888962 bytes copied in 209.920 secs (32961 bytes/sec)
Router#
Correct Answer
C. C. Erasing current flash content is requested during the copy dialog.
Explanation
During the copy process, the router asked “Erasing flash before copying? [confirm]” and the administrator confirmed (by pressing Enter) so the flash was deleted.
Note: In this case, the flash has enough space to copy a new IOS without deleting the current one. The current IOS is deleted just because the administrator wants to do so. If the flash does not have enough space you will see an error message like this:
%Error copying tftp://192.168.2.167/ c1600-k8sy-mz.l23-16a.bin (Not enough space on device)
40.
Which command reveals the last method used to powercycle a router?
Correct Answer
D. D. show version
Explanation
The “show version” command can be used to show the last method to powercycle (reset) a router
41.
Refer to the exhibit. A router boots to the prompt shown in the exhibit. What does this signify, and how should the network administrator respond?
rommon 1>
Correct Answer
C. C. The prompt signifies that the IOS image in flash memory is invalid or corrupted. The network administrator should use TFTP to transfer an IOS image to the router.
Explanation
If a Cisco router boots in ROMmon mode, it means:
+ The value of the configuration register is set to XXX0 (the boot field – fourth bit – is 0)
+ The router is unable to locate a valid Cisco IOS software image (you can use the “dir flash:” command in ROMmon mode to look for the IOS in the Flash then try to boot that flash with the “boot flash:” command).
If the IOS image is invalid or corrupted, the fastest way to re-install a new Cisco IOS software image on the router is to copy a new one from TFTP (with “tftpdnld” command).
42.
What should be done prior to backing up an IOS image to a TFTP server? (Choose three)
Correct Answer(s)
A. A. Make sure that the server can be reached across the network.
C. C. Assure that the network server has adequate space for the IOS image.
D. D. Verify file naming and path requirements.
Explanation
Prior to backing up an IOS image to a TFTP server, it is important to ensure that the server can be reached across the network. This ensures that the backup process can establish a connection and transfer the image successfully. Additionally, it is necessary to assure that the network server has adequate space to store the IOS image. This ensures that the backup process can complete without any issues related to insufficient storage. Lastly, it is important to verify file naming and path requirements to ensure that the backup process follows the correct naming conventions and saves the image in the desired location.
43.
Which two privileged mode cisco ios commands can be used to determine a cisco router chassis serial number? (choose two)
Correct Answer(s)
A. A. show inventory
D. D. show diag
Explanation
The two privileged mode Cisco IOS commands that can be used to determine a Cisco router chassis serial number are "show inventory" and "show diag". The "show inventory" command displays detailed information about the router's hardware components, including the chassis serial number. The "show diag" command provides diagnostic information about the router, including the chassis serial number. These commands can be used to retrieve the chassis serial number for identification or troubleshooting purposes.
44.
Which command helps a network administrator to manage memory by displaying flash memory and NVRAM utilization?
Correct Answer
B. B. show file systems
Explanation
The command "show file systems" helps a network administrator to manage memory by displaying flash memory and NVRAM utilization. This command provides information about the different file systems on the device, including their sizes and utilization. By using this command, the administrator can easily identify the amount of memory being used by the flash memory and NVRAM, allowing them to effectively manage and optimize memory usage on the device.
45.
A network administrator changes the configuration register to 0×2142 and reboots the router. What are two results of making this change? (Choose two)
Correct Answer(s)
B. B. The router will prompt to enter initial configuration mode.
D. D. Any configuration entries in NVRAM will be ignored.
Explanation
The router bypasses the startup configuration stored in NVRAM during its boot sequence so the router will enter initial configuration mode. This feature is normally used during a password recovery procedure.
46.
Refer to the exhibit. For what two reasons has the router loaded its IOS image from the location that is shown? (Choose two)
Router1> show version
Cisco Internetwork Operating System Software
IOS ™ 7200 Software (C7200-J-M), Experimental Version 11.3tl997091S:1647S2)
[hampton-nitro-baseline 249]
Copyright (c) 1986-1997 by cisco Systems, Inc.
Compiled Wed 08-0ct-97 06:39 by hampton
Image text-base: 0×60008900, data-base: 0x60B98000
ROM: System Bootstrap, Version 11.1(11855) [beta 2], INTERIM SOFTWARE
BOOTPLASH: 7200 Software (C7200-BOOT-M), Version 11.1(472), RELEASE SOFTWARE (fcl)
Router1 uptime is 23 hours, 33 minutes
System restarted by abort at PC 0x6022322C at 10:50:SS PDT Tue Oct 21 1997
System image file is “tftp://112.16.1.129/hampton/nitro/c7200-j-mz”
cisco 7206 (NPE150) processor with 57344K/8192K bytes of memory.
<output omitted>
Configuration register is 0×2102
Correct Answer(s)
A. A. Router1 has specific boot system command that instruct it to load IOS from TFTP server.
C. C. Router1 cannot locate a valid IOS image in flash memory.
Explanation
When powered on, the router first checks its hardware via Power-On Self Test (POST). Then it checks the configuration register to identify where to load the IOS image from. In the output above we learn that the Configuration register value is 0×2102 so the router will try to boot the system image from Flash memory first.
But we also see a line “System image file is “tftp://112.16.1.129/hampton/nitro/c7200-j-mz”. Please notice that this line tells us the image file that the device last started. In this case it is from a TFTP server. Therefore we can deduce that the router could not load the IOS image from the flash and the IOS image has been loaded from TFTP server.
Note:
If the startup-config file is missing or does not specify a location, it will check the following locations for the IOS image:
+ Flash (the default location)
+ TFTP server
+ ROM (used if no other source is found)
47.
Which of the following correctly describe steps in the OSI data encapsulation process? (Choose two)
Correct Answer(s)
A. A. The transport layer divides a data stream into segments and may add reliability and flow control information.
D. D. Packets are created when the network layer adds Layer 3 addresses and control information to a segment.
Explanation
The transport layer segments data into smaller pieces for transport. Each segment is assigned a sequence number, so that the receiving device can reassemble the data on arrival.
The transport layer also use flow control to maximize the transfer rate while minimizing the requirements to retransmit. For example, in TCP, basic flow control is implemented by acknowledgment by the receiver of the receipt of data; the sender waits for this acknowledgment before sending the next part.
-> A is correct.
The data link layer adds physical source and destination addresses and an Frame Check Sequence (FCS) to the packet (on Layer 3), not segment (on Layer 4) -> B is not correct.
Packets are created when network layer encapsulates a segment (not frame) with source and destination host addresses and protocol-related control information. Notice that the network layer encapsulates messages received from higher layers by placing them into datagrams (also called packets) with a network layer header -> C is not correct.
The Network layer (Layer 3) has two key responsibilities. First, this layer controls the logical addressing of devices. Second, the network layer determines the best path to a particular destination network, and routes the data appropriately.
-> D is correct.
The Physical layer (presentation layer) translates bits into voltages for transmission across the physical link -> E is not correct.
48.
Which layer of the OSI reference model uses the hardware address of a device to ensure message delivery to the proper host on a LAN?
Correct Answer
B. B. data link
Explanation
The hardware address of a device or the Media Access Control (MAC) address is added in the Data Link layer. An Ethernet MAC address is a 48-bit binary value expressed as 12 hexadecimal digits (for example: 00:15:A4:CB:03:CA).
49.
Which layer of the OSI reference model uses flow control, sequencing, and acknowledgments to ensure that reliable networking occurs?
Correct Answer
C. C. transport
Explanation
The transport layer of the OSI reference model is responsible for ensuring reliable networking by implementing flow control, sequencing, and acknowledgments. Flow control regulates the flow of data between the sender and receiver to prevent overwhelming the receiver. Sequencing ensures that data packets are received and delivered in the correct order. Acknowledgments are used to confirm the successful delivery of data packets and request retransmission if necessary. Therefore, the transport layer is the correct answer for this question.
50.
Which layer in the OSI reference model is responsible for determining the availability of the receiving program and checking to see if enough resources exist for that communication?
Correct Answer
E. E. application
Explanation
The application layer in the OSI reference model is responsible for determining the availability of the receiving program and checking if enough resources exist for communication. This layer interacts directly with the software application, ensuring that the necessary resources are available for successful communication. The application layer also handles tasks such as data encryption, data compression, and protocol conversion.