1.
1. What is a function of the data link layer?
Correct Answer
B. Provides for the exchange of data over a common local media
Explanation
The data link layer in a network protocol is responsible for providing the exchange of data over a common local media. This layer ensures that data is transmitted reliably between devices connected to the same network. It handles tasks such as framing, error detection and correction, and flow control. By providing a means of communication between devices on a local network, the data link layer enables the efficient and accurate transmission of data.
2.
2. Which communication tool allows real-time collaboration?
Correct Answer
D. Instant messaging
Explanation
Instant messaging allows real-time collaboration because it allows individuals to send and receive messages instantly, facilitating quick and direct communication. Unlike other communication tools such as email or a weblog, instant messaging enables users to have real-time conversations, share files, and even engage in video or audio calls, promoting efficient and interactive collaboration among individuals or teams.
3.
3. A host is accessing a Web server on a remote network. Which three functions are performed by intermediary network devices during this conversation? (Choose three.)
Correct Answer(s)
A. Regenerating data signals
D. Applying security settings to control the flow of data
E. Notifying other devices when errors occur
Explanation
During the conversation between the host and the Web server on a remote network, intermediary network devices perform three functions. Firstly, they regenerate data signals to ensure that the signals are strong and can travel long distances without degradation. Secondly, they apply security settings to control the flow of data, ensuring that unauthorized access is prevented and data integrity is maintained. Lastly, they notify other devices when errors occur, allowing for quick identification and resolution of any issues that may arise during the conversation.
4.
4. Refer to the exhibit. From which location did this router load the IOS?
Correct Answer
A. Flash memory
Explanation
The router loaded the IOS from the flash memory. Flash memory is a type of non-volatile storage that retains data even when power is lost. It is commonly used to store the operating system and other firmware on networking devices like routers. The IOS, or Internetwork Operating System, is the software that runs on Cisco routers and provides the functionality for routing and switching. Therefore, it is logical for the router to load the IOS from the flash memory, which is a permanent storage location for the operating system.
5.
5. Refer to the exhibit. Which action will be successful?
Correct Answer
C. PC2 can send a ping to 192.168.1.1.
Explanation
PC2 can send a ping to 192.168.1.1 because it is within the same network as PC2. The IP address 192.168.1.1 is within the range of the subnet that PC2 is connected to, allowing it to communicate with other devices within the same network.
6.
6. Port numbers ranging from 0 to 1023 are considered to be ............... ports
Correct Answer
well known
Explanation
Port numbers ranging from 0 to 1023 are considered to be "well known" ports. These ports are assigned by the Internet Assigned Numbers Authority (IANA) and are commonly used by well-known protocols such as HTTP (port 80), HTTPS (port 443), FTP (port 21), and SMTP (port 25). These ports are widely recognized and standardized, making them easily identifiable and commonly used by various network applications and services.
7.
7. ISOC, IANA, EIA, and IEEE represent ............... organizations which help to promote and maintain an open Internet.
Correct Answer
standards
Explanation
ISOC (Internet Society), IANA (Internet Assigned Numbers Authority), EIA (Electronic Industries Alliance), and IEEE (Institute of Electrical and Electronics Engineers) are all organizations that play a significant role in promoting and maintaining an open Internet. These organizations develop and establish standards that ensure interoperability and compatibility among different devices, networks, and technologies. By setting these standards, they contribute to the seamless functioning of the Internet and enable the exchange of information and communication on a global scale.
8.
8. Refer to the exhibit. An administrator is trying to configure the switch but receives the error message that is displayed in the exhibit. What is the problem?
Correct Answer
C. The administrator must first enter privileged EXEC mode before issuing the command.
Explanation
The error message suggests that the administrator needs to enter privileged EXEC mode before issuing the command. This means that the administrator is currently in user EXEC mode, which has limited privileges. To access global configuration mode and configure the switch, the administrator must first enter privileged EXEC mode by using the "enable" command.
9.
9. A company is expanding its business to other countries. All branch offices must remain connected to corporate headquarters at all times. Which network technology is required to support this requirement?
Correct Answer
C. WAN
Explanation
A company expanding its business to other countries requires a Wide Area Network (WAN) to support the requirement of keeping all branch offices connected to the corporate headquarters at all times. LAN (Local Area Network) is limited to a small geographical area, MAN (Metropolitan Area Network) covers a larger area but is still not suitable for connecting branch offices in different countries, and WLAN (Wireless Local Area Network) is a wireless network primarily used for local connectivity within a limited area.
10.
10. A network administrator is upgrading a small business network to give high priority to real-time applications traffic. What two types of network services is the network administrator trying to accommodate? (Choose two.)
Correct Answer(s)
C. Voice
E. Video
Explanation
The network administrator is trying to accommodate the traffic for real-time applications. Real-time applications require high priority to ensure smooth and uninterrupted communication. Voice and video are examples of real-time applications that require high priority to maintain the quality of the communication. SNMP, instant messaging, and FTP are not real-time applications and do not require high priority for traffic.
11.
12. Which IPv4 address can be pinged to test the internal TCP/IP operation of a host?
Correct Answer
C. 127.0.0.1
Explanation
The IPv4 address 127.0.0.1, also known as the loopback address, can be pinged to test the internal TCP/IP operation of a host. This address is reserved for testing network software and communication between processes on the same host. When a packet is sent to this address, it is looped back and delivered to the sender's own network stack. This allows the host to verify that its TCP/IP stack is functioning correctly.
12.
13. What three application layer protocols are part of the TCP/IP protocol suite? (Choose three.)
Correct Answer(s)
B. DHCP
C. DNS
D. FTP
Explanation
The three application layer protocols that are part of the TCP/IP protocol suite are DHCP, DNS, and FTP. DHCP (Dynamic Host Configuration Protocol) is responsible for assigning IP addresses to devices on a network. DNS (Domain Name System) translates domain names into IP addresses. FTP (File Transfer Protocol) is used for transferring files between a client and a server on a network. ARP (Address Resolution Protocol), NAT (Network Address Translation), and PPP (Point-to-Point Protocol) are not application layer protocols in the TCP/IP suite.
13.
14. Which two protocols function at the internet layer? (Choose two)
Correct Answer(s)
C. ICMP
D. IP
Explanation
ICMP (Internet Control Message Protocol) and IP (Internet Protocol) function at the internet layer. ICMP is responsible for sending error messages and operational information about network conditions. IP is responsible for routing packets across different networks. Both protocols work together to ensure proper communication between devices on the internet.
14.
15. Which publicly available resources describe protocols, processes, and technologies for the Internet but do not give implementation details?
Correct Answer
A. Request for Comments
Explanation
Request for Comments (RFCs) are documents that describe protocols, processes, and technologies for the Internet. They are publicly available resources that provide information and guidelines for the development and implementation of Internet standards. However, RFCs do not give implementation details. They focus more on the conceptual and theoretical aspects of the protocols, providing a framework for their implementation rather than specific instructions on how to implement them.
15.
16. Which address on a PC does not change, even if the PC is moved to a different network?
Correct Answer
C. MAC address
Explanation
The MAC address is a unique identifier assigned to the network interface card (NIC) of a device. It remains constant regardless of the network the PC is connected to. The MAC address is used for communication within the local network, while the IP address is used for communication over the internet. The default gateway address and logical address can vary depending on the network configuration, making the MAC address the only option that does not change when the PC is moved to a different network.
16.
17. What is the protocol that is used to discover a physical address from a known logical address and what message type does it use?
Correct Answer
D. ARP, broadcast
Explanation
ARP (Address Resolution Protocol) is used to discover a physical address (MAC address) from a known logical address (IP address). ARP uses broadcast messages to send a request to all devices on the network, asking for the MAC address associated with a specific IP address. The device that has the requested IP address will respond with its MAC address, allowing the sender to establish a direct communication link.
17.
18. What will happen if the default gateway address is incorrectly configured on a host?
Correct Answer
D. The host cannot communicate with hosts in other networks.
Explanation
If the default gateway address is incorrectly configured on a host, the host will not be able to communicate with hosts in other networks. The default gateway is responsible for routing traffic between different networks. If the address is incorrect, the host will not be able to send packets to the correct gateway, resulting in the inability to communicate with hosts in other networks.
18.
19. What is an important function of the physical layer of the OSI model?
Correct Answer
D. It encodes frames into electrical, optical, or radio wave signals.
Explanation
The physical layer of the OSI model is responsible for transmitting raw data bits over a communication channel. It takes the frames received from the data link layer and encodes them into electrical, optical, or radio wave signals that can be transmitted through the physical media. This encoding process ensures that the data can be effectively transmitted over the chosen medium and decoded correctly by the receiving device. Therefore, encoding frames into electrical, optical, or radio wave signals is an important function of the physical layer.
19.
20. Which two statements describe the characteristics of fiber-optic cabling? (Choose two.)
Correct Answer(s)
A. Fiber-optic cabling does not conduct electricity.
C. Fiber-optic cabling is primarily used as backbone cabling.
Explanation
Fiber-optic cabling does not conduct electricity because it is made of glass or plastic fibers that transmit data using light signals instead of electrical signals. This characteristic makes it ideal for environments where electrical interference is a concern, such as in hospitals or industrial settings. Additionally, fiber-optic cabling is primarily used as backbone cabling because it has a high bandwidth capacity and can transmit data over long distances without significant signal loss. This makes it suitable for connecting network switches and routers in large-scale networks.
20.
21. What is contained in the trailer of a data-link frame?
Correct Answer
D. Error detection
Explanation
The trailer of a data-link frame contains error detection information. This is important for ensuring the integrity of the data being transmitted. By including error detection in the trailer, the receiver can check if any errors occurred during transmission and take appropriate action, such as requesting retransmission of the data. This helps to maintain the reliability and accuracy of the data being transmitted over the data-link layer.
21.
22. Refer to the exhibit. A ping to PC3 is issued from PC0, PC1, and PC2 in this exact order. Which MAC addresses will be contained in the S1 MAC address table that is associated with the Fa0/1 port?
Correct Answer
A. Just PC0 and PC1 MAC addresses
Explanation
When a ping is issued from PC0, PC1, and PC2 in that order, the MAC addresses of PC0 and PC1 will be learned by the switch S1 on its Fa0/1 port. The switch will update its MAC address table with the MAC addresses of the devices that are directly connected to it. Since the ping from PC2 is issued after PC1, the switch will not have learned the MAC address of PC2 yet. Therefore, only the MAC addresses of PC0 and PC1 will be contained in the S1 MAC address table associated with the Fa0/1 port.
22.
23. How does a Layer 3 switch differ from a Layer 2 switch?
Correct Answer
B. An IP address can be assigned to a pHysical port of a Layer 3 switch. However, this is not supported in Layer 2 switches.
Explanation
A Layer 3 switch differs from a Layer 2 switch because it allows for the assignment of an IP address to a physical port. In contrast, Layer 2 switches do not support this feature. This ability to assign IP addresses to ports is a key distinction between the two types of switches, making Layer 3 switches more versatile in terms of network configuration and routing capabilities.
23.
24. What is the purpose of the routing process?
Correct Answer
B. To select the paths that are used to direct traffic to destination networks
Explanation
The purpose of the routing process is to select the paths that are used to direct traffic to destination networks. Routing involves determining the most efficient path for data packets to travel from the source to the destination network. This is done by analyzing network topology, network congestion, and other factors to make decisions on the best routes. Routing ensures that data packets reach their intended destinations in a timely and efficient manner, optimizing network performance.
24.
25. Which technology provides a solution to IPv4 address depletion by allowing multiple devices to share one public IP address?
Correct Answer
C. NAT
Explanation
NAT (Network Address Translation) is the technology that provides a solution to IPv4 address depletion by allowing multiple devices to share one public IP address. NAT works by translating private IP addresses used within a local network into a single public IP address that is visible on the internet. This allows multiple devices to access the internet using a single public IP address, conserving the limited number of available IPv4 addresses.
25.
26. Refer to the exhibit. Consider the IP address configuration shown from PC1. What is a description of the default gateway address?
Correct Answer
B. It is the IP address of the Router1 interface that connects the PC1 LAN to Router1.
Explanation
The default gateway address refers to the IP address of the Router1 interface that connects the PC1 LAN to Router1. This means that any traffic from PC1 that is not destined for the local LAN will be sent to the default gateway, which is Router1, for further routing to other networks.
26.
27. Which of the following are primary functions of a router? (Choose two.)
Correct Answer(s)
A. Packet switching
D. Path selection
Explanation
A router is a networking device that connects multiple networks and directs network traffic between them. One of the primary functions of a router is packet switching, which involves receiving packets of data and determining the most efficient path to forward them to their destination. Another primary function is path selection, where the router analyzes different paths and selects the best one based on factors like speed, cost, and reliability. Microsegmentation, domain name resolution, and flow control are not primary functions of a router.
27.
28. Which two statements correctly describe a router memory type and its contents? (Choose two.)
Correct Answer(s)
A. ROM is nonvolatile and contains basic diagnostic software.
D. RAM is volatile and stores the IP routing table.
Explanation
ROM is nonvolatile and contains basic diagnostic software. This statement is correct because ROM (Read-Only Memory) is a type of memory in a router that retains its contents even when the power is turned off. It contains the basic diagnostic software that is used during the boot process to initialize the router's hardware and perform self-tests.
RAM is volatile and stores the IP routing table. This statement is also correct because RAM (Random Access Memory) is a type of memory in a router that is used for temporary storage of data and instructions. It is volatile, meaning that its contents are lost when the power is turned off. The IP routing table, which contains information about the network paths and next hops, is stored in RAM for quick access and efficient routing decision-making.
28.
29. In which default order will a router search for startup configuration information?
Correct Answer
B. NVRAM, TFTP, setup mode
Explanation
A router will first search for startup configuration information in NVRAM (Non-Volatile Random Access Memory), which is a type of memory that retains data even when the router is powered off. If the configuration is not found in NVRAM, the router will then search for it in TFTP (Trivial File Transfer Protocol), which allows the router to retrieve configuration files from a remote server. Finally, if the configuration is still not found, the router will enter setup mode, where a basic configuration can be manually entered.
29.
30. What happens when part of an Internet VoIP transmission is not delivered to the destination?
Correct Answer
D. The transmission continues without the missing portion.
Explanation
When part of an Internet VoIP transmission is not delivered to the destination, the transmission continues without the missing portion. This means that the missing part is not re-sent or replaced, but the transmission carries on with the remaining data. This is because VoIP technology is designed to prioritize real-time communication, so it is more important to maintain the flow of the conversation rather than waiting for missing data to be re-sent.
30.
31. Which three IP addresses are private ? (Choose three.)
Correct Answer(s)
A. 10.172.168.1
D. 172.20.4.4
E. 192.168.5.254
Explanation
The three private IP addresses are 10.172.168.1, 172.20.4.4, and 192.168.5.254. Private IP addresses are reserved for internal use within a private network and are not routable on the internet. These addresses are commonly used in home and office networks for devices such as computers, printers, and routers. The other IP addresses listed in the question (172.32.5.2, 192.167.10.10, and 224.6.6.6) are not private IP addresses as they fall within ranges that are designated for public use or multicast purposes.
31.
32. How many bits make up the single IPv6 hextet :10CD:?
Correct Answer
C. 16
Explanation
The single IPv6 hextet :10CD: is made up of 16 bits. In IPv6, each hextet consists of 4 hexadecimal digits, and each hexadecimal digit represents 4 bits. Therefore, multiplying 4 hexadecimal digits by 4 bits per digit gives us a total of 16 bits in a single IPv6 hextet.
32.
33. What is the effect of configuring the ipv6 unicast-routing command on a router?
Correct Answer
B. To enable the router as an IPv6 router
Explanation
Configuring the "ipv6 unicast-routing" command on a router enables the router to function as an IPv6 router. This command allows the router to forward IPv6 unicast traffic between different networks. By enabling this command, the router will be able to process and route IPv6 packets, allowing for the successful transmission of data across IPv6 networks.
33.
34. Which group of IPv6 addresses cannot be allocated as a host source address?
Correct Answer
D. FF00::/8
Explanation
The FF00::/8 IPv6 address range cannot be allocated as a host source address. This range is reserved for multicast addresses, which are used for one-to-many communication. Multicast addresses are not assigned to individual hosts, but rather to groups of hosts that are interested in receiving the multicast traffic. Therefore, this address range cannot be used as a source address for individual hosts.
34.
35. What is the purpose of ICMP messages?
Correct Answer
C. To provide feedback of IP packet transmissions
Explanation
ICMP (Internet Control Message Protocol) messages are used to provide feedback about the transmission of IP packets. These messages are sent by network devices, such as routers, to inform the sender about the status of the transmitted packets. ICMP messages can indicate whether a packet has been successfully delivered, encountered an error, or was unable to reach its destination. By receiving this feedback, the sender can take appropriate actions, such as retransmitting the packet or adjusting its transmission parameters. Therefore, the purpose of ICMP messages is to provide feedback and assist in the reliable delivery of IP packets.
35.
36. Refer to the exhibit. A technician has configured a user workstation with the IP address and default subnet masks that are shown. Although the user can access all local LAN resources, the user cannot access any Internet sites by using either FQDN or IP addresses. Based upon the exhibit, what could account for this failure?
Correct Answer
B. The default gateway address in incorrect.
Explanation
The default gateway address being incorrect could account for the user's inability to access Internet sites. The default gateway is responsible for routing traffic between different networks, including the local LAN and the Internet. If the default gateway address is incorrect, the user's requests to access Internet sites would not be properly routed, resulting in the failure to connect.
36.
37. A network administrator needs to monitor network traffic to and from servers in a data center. Which features of an IP addressing scheme should be applied to these devices?
Correct Answer
C. Predictable static IP addresses for easier identification
Explanation
Predictable static IP addresses should be applied to the servers in a data center for easier identification. This means that each server is assigned a specific IP address that does not change, making it easier for the network administrator to identify and manage the servers. This is particularly useful in a data center where there may be a large number of servers that need to be monitored. Using predictable static IP addresses ensures that the administrator can easily locate and troubleshoot any issues with the servers.
37.
38. Refer to the exhibit. Which IP addressing scheme should be changed?
Correct Answer
B. Site 2
38.
39. Which two notations are useable nibble boundaries when subnetting in IPv6? (Choose two.)
Correct Answer(s)
B. /64
D. /68
Explanation
The correct answer is /64 and /68. In IPv6 subnetting, a nibble boundary refers to dividing the subnet into groups of 4 bits. Both /64 and /68 fall on nibble boundaries because they can be evenly divided by 4. Subnetting on a nibble boundary is recommended in IPv6 to simplify network management and ensure compatibility with various devices.
39.
40. A host PC has just booted and is attempting to lease an address through DHCP. Which two messages will the client typically broadcast on the network? (Choose two.)
Correct Answer(s)
A. DHCPDISCOVER
C. DHCPREQUEST
Explanation
When a host PC boots and attempts to lease an address through DHCP, it will typically broadcast two messages on the network. The first message is DHCPDISCOVER, which is a broadcast message sent by the client to discover DHCP servers available on the network. The second message is DHCPREQUEST, which is a broadcast message sent by the client to request an IP address from a specific DHCP server.
40.
41. What is the purpose of the network security accounting function?
Correct Answer
C. To keep track of the actions of a user
Explanation
The purpose of the network security accounting function is to keep track of the actions of a user. This helps in monitoring and logging the activities performed by users on the network, allowing for accountability and traceability. It helps identify any unauthorized or suspicious activities, and assists in forensic investigations if any security incidents occur. Additionally, network security accounting helps in generating reports and audits for compliance purposes, ensuring that the network is secure and that users are adhering to the organization's security policies.
41.
42. Refer to the exhibit. The network administrator enters these commands into the R1 router:
R1# copy running-config tftp
Address or name of remote host [ ]?
When the router prompts for an address or remote host name, what IP address should the administrator enter at the prompt?
Correct Answer
D. 192.168.11.252
Explanation
The IP address that the administrator should enter at the prompt is 192.168.11.252. This is because the command "copy running-config tftp" is used to copy the running configuration of the router to a TFTP server. The prompt is asking for the address or name of the remote host, which in this case is the TFTP server. Therefore, the administrator should enter the IP address of the TFTP server, which is 192.168.11.252.
42.
44. What two preconfigured settings that affect security are found on most new wireless routers? (Choose two.)
Correct Answer(s)
A. Broadcast SSID
E. Default administrator password
Explanation
The two preconfigured settings that affect security found on most new wireless routers are "broadcast SSID" and "default administrator password". The broadcast SSID setting determines whether the wireless network name is visible to other devices, while the default administrator password is the initial password used to access the router's settings. These settings can impact the security of the network as hiding the SSID can make it harder for unauthorized users to detect the network, and changing the default administrator password prevents unauthorized access to the router's settings.
43.
45. Which type of wireless security generates dynamic encryption keys each time a client associates with an AP?
Correct Answer
D. WPA
Explanation
WPA (Wi-Fi Protected Access) is a type of wireless security that generates dynamic encryption keys each time a client associates with an Access Point (AP). This ensures that the encryption keys are constantly changing, making it more difficult for unauthorized users to intercept and decrypt the wireless network traffic. EAP (Extensible Authentication Protocol) is a framework for authentication, but it does not specifically generate dynamic encryption keys. PSK (Pre-Shared Key) is a method that uses a single key for all devices on the network, so it does not generate dynamic keys. WEP (Wired Equivalent Privacy) is an older and less secure wireless security protocol that also does not generate dynamic keys.
44.
46. ........ is a best-effort, connectionless application layer protocol that is used to transfer files.
Correct Answer
TFTP
Explanation
TFTP (Trivial File Transfer Protocol) is a best-effort, connectionless application layer protocol used for transferring files. It is designed to be simple and lightweight, making it suitable for transferring small files in network environments with limited resources. TFTP operates on UDP (User Datagram Protocol) and does not provide reliable data transfer or error correction mechanisms. It is commonly used in scenarios such as booting diskless workstations or transferring firmware updates to network devices.
45.
47. Which two components are necessary for a wireless client to be installed on a WLAN? (Choose two.)
Correct Answer(s)
B. Wireless NIC
F. Wireless client software
Explanation
A wireless client needs two components to be installed on a WLAN: a wireless NIC (Network Interface Card) and wireless client software. The wireless NIC allows the device to connect to the wireless network by sending and receiving signals. The wireless client software is necessary to manage the connection and communicate with the wireless network.
46.
48. The prefix-length for the range of addresses is .....
Correct Answer(s)
60
Explanation
The prefix-length for the range of addresses is 60. A prefix-length is used in IP addressing to determine the network portion of an IP address. It specifies the number of bits in the network portion of the address. In this case, a prefix-length of 60 indicates that the first 60 bits of the address are used to identify the network, while the remaining bits are used to identify the host within that network.
47.
50. A host is accessing an FTP server on a remote network. Which three functions are performed by intermediary network devices during this conversation? (Choose three.)
Correct Answer(s)
A. Regenerating data signals
D. Applying security settings to control the flow of data
E. Notifying other devices when errors occur
Explanation
During the conversation between the host and the FTP server, intermediary network devices perform three functions. Firstly, they regenerate data signals to ensure that the signals remain strong and clear as they travel across the network. Secondly, they apply security settings to control the flow of data, ensuring that unauthorized access is prevented and data integrity is maintained. Lastly, these devices notify other devices when errors occur, allowing for prompt troubleshooting and resolution of any issues that may arise during the conversation.
48.
51. When is a dial-up connection used to connect to an ISP?
Correct Answer
D. When a regular telepHone line is used
Explanation
A dial-up connection is used to connect to an ISP when a regular telephone line is used. This is because dial-up connections use the existing telephone infrastructure to establish a connection to the internet. The user's computer dials a specific phone number provided by the ISP, and the modem on the computer establishes a connection with the ISP's modem through the telephone line. The data is then transmitted over the telephone line to access the internet. Dial-up connections are slower compared to other types of connections like cable or fiber-optic, but they can be used in areas where high-speed connections are not available.
49.
52. On a school network, students are surfing the web, searching the library database, and attending an audio conference with their sister school in Japan. If network traffic is prioritized with QoS, how will the traffic be classified from highest priority to lowest priority?
Correct Answer
A. Audio conference, database, HTTP
Explanation
The correct answer is audio conference, database, HTTP. In a school network where QoS is implemented, the highest priority would be given to real-time applications like audio conferences, as they require low latency and uninterrupted transmission. The next priority would be given to accessing the library database, as it involves retrieving and updating important information. The lowest priority would be given to HTTP traffic, which includes web browsing, as it is not as time-sensitive or critical as the other two activities.
50.
53. During normal operation, from which location do most Cisco routers run the IOS?
Correct Answer
A. RAM
Explanation
During normal operation, most Cisco routers run the IOS from RAM. RAM (Random Access Memory) is a type of computer memory that allows data to be accessed quickly. Running the IOS from RAM allows the router to execute commands and processes efficiently. Flash memory is used to store the IOS image, but it is typically copied to RAM for execution. NVRAM (Non-Volatile Random Access Memory) is used to store the router's startup configuration, and a disk drive is not typically used to run the IOS.