CISCO Cyberops Security Fundamentals Section 02: Network Infrastructure (Q 1-10)

1. In the address 172.16.55.87 /20, what does the /20 indicate?

The subnet can accommodate 20 hosts per network

This subnet is the 20th usable range

This IP address is the 20th usable IP in the range

The /20 in the given address indicates the prefix length, where the first 20 bits are the network address and the remaining 12 bits are the host portion.

Explanation

The /20 in the given address indicates the prefix length, where the first 20 bits are the network address and the remaining 12 bits are the host portion.

2. Which one of the following devices operates strictly at the physical layer?

Switches

Hubs

Routers

Bridges

Hubs operate strictly at the physical layer. A hub is a networking device that connects multiple devices in a network, allowing them to communicate with each other. It simply receives incoming data packets and broadcasts them to all connected devices without any intelligence or filtering. Hubs do not perform any network routing or make decisions based on IP addresses, making them operate only at the physical layer of the network protocol stack.

Explanation

Hubs operate strictly at the physical layer. A hub is a networking device that connects multiple devices in a network, allowing them to communicate with each other. It simply receives incoming data packets and broadcasts them to all connected devices without any intelligence or filtering. Hubs do not perform any network routing or make decisions based on IP addresses, making them operate only at the physical layer of the network protocol stack.

3. Which one of the following options is the main purpose for using spanning tree protocol?

Layer 2 routing protocol

Layer 2 loop prevention protocol

Layer 2 frame speed double verification protocol

Layer 3 routing protocol

The main purpose of using the spanning tree protocol is to prevent layer 2 loops in a network. Layer 2 loops can occur when there are multiple paths between switches, causing broadcast storms and network congestion. The spanning tree protocol helps to identify and disable redundant paths, ensuring that there is only one active path between switches. This prevents loops and improves network stability and performance.

Explanation

The main purpose of using the spanning tree protocol is to prevent layer 2 loops in a network. Layer 2 loops can occur when there are multiple paths between switches, causing broadcast storms and network congestion. The spanning tree protocol helps to identify and disable redundant paths, ensuring that there is only one active path between switches. This prevents loops and improves network stability and performance.

4. Which one of the following statements is true regarding STP?

STP is used to defend against spoofing attacks.

STP is used to maintain the VLAN configuration consistency across the Layer 2 network.

STP is used to negotiate whether an interconnection between two switches should be put into access or trunk mode.

STP is used to detect the loss of bidirectional communication on a link.

STP, or Spanning Tree Protocol, is used to prevent loops from forming in a Layer 2 network when switches or bridges are interconnected via multiple paths. By identifying redundant links and blocking certain paths, STP ensures that there is only one active path between any two network devices, thus preventing broadcast storms and network instability caused by loops. This helps to maintain network reliability and efficiency.

Explanation

STP, or Spanning Tree Protocol, is used to prevent loops from forming in a Layer 2 network when switches or bridges are interconnected via multiple paths. By identifying redundant links and blocking certain paths, STP ensures that there is only one active path between any two network devices, thus preventing broadcast storms and network instability caused by loops. This helps to maintain network reliability and efficiency.

5. When using DHCP with LWAP devices, which one of the following is option 43 used for?

To identify the default gateway

To assign a fallback IP address

To supply the specific WLAN controllers IP address

To supply the specific NAME server IP address

Option 43 is used in DHCP with LWAP devices to supply the specific WLAN controllers IP address. This means that when a LWAP device connects to the network and obtains an IP address through DHCP, it can also receive the IP address of the specific WLAN controller that it should associate with. This allows the LWAP device to establish a connection with the appropriate WLAN controller and join the wireless network.

Explanation

Option 43 is used in DHCP with LWAP devices to supply the specific WLAN controllers IP address. This means that when a LWAP device connects to the network and obtains an IP address through DHCP, it can also receive the IP address of the specific WLAN controller that it should associate with. This allows the LWAP device to establish a connection with the appropriate WLAN controller and join the wireless network.

6. Match the following

acts as a Layer 1 repeater device

forwards Ethernet frames based on the destination MAC address

bridging operations that are performed in hardware rather than software

limits broadcast domain

Submit

7. How many usable subnets and hosts per subnet are available in the 192.168.1.0 network address with a 255.255.255.240 mask?

2 usable subnets and 126 hosts per subnet

4 usable subnets and 62 hosts per subnet

8 usable subnets and 30 hosts per subnet

16 usable subnets and 14 hosts per subnet

32 usable subnets and 6 hosts per subnet

The given network address 192.168.1.0 with a 255.255.255.240 mask allows for 16 usable subnets. This is because the subnet mask 255.255.255.240 has 4 bits borrowed from the host portion, which gives us 2^4 = 16 subnets. Each subnet can have 14 hosts, as the remaining 4 bits in the host portion can represent 2^4 - 2 = 14 hosts per subnet.

Explanation

The given network address 192.168.1.0 with a 255.255.255.240 mask allows for 16 usable subnets. This is because the subnet mask 255.255.255.240 has 4 bits borrowed from the host portion, which gives us 2^4 = 16 subnets. Each subnet can have 14 hosts, as the remaining 4 bits in the host portion can represent 2^4 - 2 = 14 hosts per subnet.

8. Which two of the following DHCP messages are always sent as broadcast? (Choose two.)

DHCPOFFER

DHCPDISCOVER

DHCPREQUEST

DHCPACK

The DHCPDISCOVER and DHCPREQUEST messages are always sent as broadcast. DHCPDISCOVER is sent by a client to discover available DHCP servers on the network, and it needs to be sent as a broadcast so that all DHCP servers can receive it. DHCPREQUEST is sent by the client to request a specific IP address from a DHCP server, and again, it needs to be sent as a broadcast so that all DHCP servers can hear the request and respond accordingly.

Explanation

The DHCPDISCOVER and DHCPREQUEST messages are always sent as broadcast. DHCPDISCOVER is sent by a client to discover available DHCP servers on the network, and it needs to be sent as a broadcast so that all DHCP servers can receive it. DHCPREQUEST is sent by the client to request a specific IP address from a DHCP server, and again, it needs to be sent as a broadcast so that all DHCP servers can hear the request and respond accordingly.

Submit

9. Which two of the following options are potential problems with a large single broadcast domain? (Choose two.)

Large amounts of broadcast traffic consume resources.

All PCs share the same collision domain.

Layer 3 routing overhead is high.

It is difficult to apply security policies because there are no boundaries between devices.

A large single broadcast domain can lead to potential problems such as consuming excessive network resources due to the high volume of broadcast traffic. This can cause congestion and slow down the network. Additionally, without boundaries between devices, it becomes challenging to apply security policies effectively, leaving the network vulnerable to unauthorized access and potential security breaches.

Explanation

A large single broadcast domain can lead to potential problems such as consuming excessive network resources due to the high volume of broadcast traffic. This can cause congestion and slow down the network. Additionally, without boundaries between devices, it becomes challenging to apply security policies effectively, leaving the network vulnerable to unauthorized access and potential security breaches.

Submit

10. Which two of the following statements are true regarding standalone and lightweight access points? (Choose two.)

Lightweight access points are self-contained, each offering one or more fully functional BSSs.

Standalone access points can be configured one-by-one and offer complete functionality by themselves.

Lightweight access points rely on a central wireless LAN controller to retrieve their configurations.

Lightweight access points are also known as autonomous access points.

Standalone access points can be configured individually and provide full functionality on their own, while lightweight access points require a central wireless LAN controller to obtain their configurations.

Explanation

Standalone access points can be configured individually and provide full functionality on their own, while lightweight access points require a central wireless LAN controller to obtain their configurations.

Submit