To establish a secure web connection to YouTube.com, the computer will run two protocols: DNS and HTTPS. DNS (Domain Name System) is a protocol that translates domain names into IP addresses, which are used to identify and locate web servers on the internet. HTTPS (Hypertext Transfer Protocol Secure) is a protocol that encrypts and authenticates data transfer between a web browser and a web server, ensuring the security and integrity of the communication.

The computer does not need to run DHCP (Dynamic Host Configuration Protocol), FTP (File Transfer Protocol), or HTTP5 (a non-existent protocol) to connect to YouTube.com. DHCP is a protocol that assigns IP addresses to devices on a network automatically, but the computer already has a static address configured. FTP is a protocol that transfers files between a client and a server, but it is not used for web browsing. HTTP5 is not a valid protocol name, and it is likely a typo for HTTP (Hypertext Transfer Protocol), which is the unsecure version of HTTPS. References:

• Aruba Certified Network Technician (ACNT) | HPE Aruba Networking
• 6 Network Security Protocols You Should Know | Cato Networks
• What is HTTPS? | Cloudflare

 Adjacent Channel Interference (ACI) is a type of interference that occurs when two or more wireless devices use channels that are close to each other in the same frequency band. ACI reduces the signal quality and throughput of the wireless devices, as they have to compete for the same spectrum and deal with the noise from the neighboring channels12

The 5 GHz band has more non-overlapping channels than the 2.4 GHz band, which means that there is less chance of ACI in the 5 GHz band. However, ACI can still occur in the 5 GHz band if the wireless devices use wider channel bandwidths, such as 40 MHz or 80 MHz, which are supported by 802.11n and 802.11ac standards. Wider channel bandwidths can increase the data rate and performance of the wireless devices, but they also occupy more spectrum and reduce the number of available channels134

Therefore, one condition that allows 5 GHz channels to avoid ACI is to transmit at 20 MHz bandwidth, which is the narrowest channel bandwidth supported by 802.11a/n/ac standards. By transmitting at 20 MHz bandwidth, the wireless devices can use more non-overlapping channels in the 5 GHz band and minimize the impact of ACI. However, this alsomeans that the wireless devices will have lower data rates and performance than using wider channel bandwidths134

Another condition that can help avoid ACI in the 5 GHz band is to use channel bonding, which is a technique that combines two or more adjacent channels into one wider channel. Channel bonding can increase the data rate and performance of the wireless devices, but it also requires careful planning and coordination to avoid overlapping with other wireless devices. Channel bonding can be done with 40 MHz or 80 MHz channel bandwidths, but not with 20 MHz channel bandwidths134 References: 

https://www.ti.com/pdfs/bcg/80211_acr_wp.pdf

https://www.ti.com/pdfs/bcg/80211_acr_wp.pdf

OWE is a Wi-Fi technology that assists with data privacy on open networks by providing unauthenticated data encryption. OWE is based on the standard defined in RFC 8110, which specifies an extension to IEEE 802.11 that uses a cryptographic handshake to encrypt the devices connecting to open network access points. OWE reduces the risk of data exposure or theft when using an open Wi-Fi network, without adding complexity or scalability burdens. OWE is part of the Wi-Fi CERTIFIED Enhanced Open™ program, which is a new certification for Wi-Fi devices that support this technology123 References:

• Wi-Fi CERTIFIED Enhanced Open™: Transparent Wi-Fi … - Wi-Fi Alliance
• Debunking Wi-Fi® Security Myths: Cellular Networks are … - TechSpective
• 10. Use adequate security to send or receive health information over …

A device that provides high ethernet port density for connecting wired clients is a switch. A switch is a device that operates at the data link layer (layer two) of the OSI model and forwards frames between devices on the same network based on their MAC addresses1. A switch can have multiple ports, ranging from 8 to 48 or more, that can connect to various wired devices, such as computers, IP phones, and printers2. A multilayer switch is a switch that can also operate at the network layer (layer three) of the OSI model and perform routing functions based on IP addresses3. Therefore, statements D and E are correct. Statements A, B, and C are incorrect because they describe devices that provide wireless connectivity, not wired connectivity. A wireless router is a device that combines the functions of a router and an access point and provides wireless access to the internet. A router is a device that operates at the network layer (layer three) of the OSI model and forwards packets between different networks based on their destination IP addresses. An access point is a device that connects wireless devices to a wired network and acts as a bridge between the two. References: 1: Aruba Certified Network Technician (ACNT) Study Guide, page 282: Aruba Certified Network Technician (ACNT) Study Guide, page 303: Aruba Certified Network Technician (ACNT) Study Guide, page 32. : Aruba Certified Network Technician (ACNT) Study Guide, page 29. : Aruba Certified Network Technician (ACNT) Study Guide, page 29. : Aruba Certified Network Technician (ACNT) Study Guide, page 94.

The Institute of Electrical and Electronics Engineers (IEEE) is an organization that develops and publishes international standards for various fields of engineering, including electrical, electronic, computer, software, and telecommunications. IEEE standards are widely used and recognized by the industry, academia, and governments. IEEE standards cover topics such as wireless networking, Ethernet, power systems, smart grid, cybersecurity, robotics, biomedical engineering, and more. IEEE standards are developed by consensus among experts from different sectors and regions, and are reviewed and updated regularly to reflect the latest technologies and best practices. IEEE standards aim to promote innovation, interoperability, safety, reliability, and efficiency in engineering applications. References: IEEE Standards Association, IEEE - Wikipedia, IEEE Standards - Creative Safety Supply

ARP is a protocol that maps an IP address to a MAC address, which is the physical address of a device on a network. ARP is necessary because the software address (IP address) of the host or computer connected to the network needs to be translated to a hardware address (MAC address). Without ARP, a host would not be able to figure out the hardware address of another host. ARP works by sending a broadcast message to all devices on the network, asking for the MAC address of the device that has a specific IP address. The device that has that IP address replies with its MAC address, and the sender stores this information in its ARP cache for future use. The sender then uses the MAC address as the destination address of the Layer 2 header that encapsulates the IP packet. The Layer 2 header is also known as the data link layer header, which is responsible for delivering the packet to the correct device on the same network. The Layer 3 header is also known as the network layer header, which is responsible for routing the packet to the correct network. Therefore, the correct answer is C, because ARP is used to discover the destination address of the Layer 2 header that encapsulates IP packets1234 References: What Is Address Resolution Protocol (ARP)? - Fortinet, Address Resolution Protocol - Wikipedia, ARP (Address Resolution Protocol) explained - Study-CCNA, Aruba Certified Network Technician Exam HPE3-U01 Actual Questions

Broadcast communication is the distribution of audio or video content to a dispersed audience via any electronic mass communications medium, using the electromagnetic spectrum (radio waves), in a one-to-many model1. A broadcast message is a message that is sent to all endpoints on the network, regardless of their address or identity2. An example of a broadcast message is an ARP request, which is used to find the MAC address of a device that has a specific IP address3. An ARP request is sent to the broadcast address of the network, which is usually the last address in the subnet (e.g., 192.168.1.255 for a /24 network). All devices on the network receive the ARP request and check if their IP address matches the one in the request. If so, they reply with their MAC address to the sender of the ARP request. If not, they ignore the request4. Therefore, an ARP request is an example of broadcast communication, while the other options are not. A DHCP offer is a message that is sent by a DHCP server to a specific client that requested an IP address5. An ICMP echo is a message that is sent by a device to test the connectivity and latency to another device. An HTTP Get is a message that is sent by a web browser to request a web page from a web server. These messages are not broadcast, but rather unicast, meaning they are sent to a single destination. References: 1: Broadcasting - Wikipedia 2: Broadcast communication network - Wikipedia 3: [Address Resolution Protocol - Wikipedia] 4: [How ARP Works - Cisco] 5: [DHCP - Wikipedia] : [Ping (networking utility) - Wikipedia] : [Hypertext Transfer Protocol - Wikipedia] : https://en.wikipedia.org/wiki/Address_Resolution_Protocol : https://www.cisco.com/c/en/us/support/docs/ip/dynamic-address-allocation- resolution/13718-5.html : https://en.wikipedia.org/wiki/Dynamic_Host_Configuration_Protocol : https://en.wikipedia.org/wiki/Ping_(networking_utility) : https://en.wikipedia.org/wiki/Hypertext_Transfer_Protocol

The binary equivalent of the decimal number of 233 is 11101001. To find this, we can use the following method:

• Divide 233 by 2 and write down the remainder. The remainder is either 0 or 1.
• Divide the quotient by 2 and write down the new remainder.
• Repeat this process until the quotient is 0.
• Write the remainders from the bottom to the top. This is the binary equivalent.

For example:

Table

Quotient

Remainder

233 / 2

1

116 / 2

0

58 / 2

0

29 / 2

1

14 / 2

0

7 / 2

1

3 / 2

1

1 / 2

1

0 / 2

0

The remainders from the bottom to the top are 11101001, which is the binary equivalent of 233.

References:

1: Decimal to Binary Converter - RapidTables 2: How to Convert Decimal to Binary - wikiHow 3: Decimal to Binary Conversion Methods - GeeksforGeeks

In order to allow inter-PC communication in the same broadcast domain, both switches need to have the same VLAN configured on the ports that connect to the PCs and the trunk port that connects to each other. Option B shows the correct configuration for both switches, as follows:

• On Switch-1, interface 0/1 is configured as an access port on VLAN 10, which matches the VLAN of PC-1. Interface 0/2 is configured as a trunk port, which allows VLAN 10 traffic to pass through to Switch-2.
• On Switch-2, interface 0/1 is configured as an access port on VLAN 10, which matches the VLAN of PC-2. Interface 0/2 is also configured as a trunk port, which allows VLAN 10 traffic to pass through from Switch-1.

Option A is incorrect because it does not configure the trunk port on Switch-2, which prevents VLAN 10 traffic from reaching Switch-1. Option C is incorrect because it configures the trunk port on Switch-1 with the wrong encapsulation mode (ISL instead of dot1q), which causes a mismatch with Switch-2. Option D is incorrect because it configures the access ports on Switch-2 with the wrong VLAN (20 instead of 10), which isolates PC-2 from PC-1.

References:

1: Layer 2 VLAN Configuration on a Cisco Switch (with Example) - Networks Training 2: VLAN Configuration Commands Step by Step Explained - Computer Networking Notes 3: How To Configure VLANs On the Catalyst Switches - Cisco Community 4: Configure VLAN on Cisco Switch Using Cisco Packet Tracer - TECHNIG

 A switch is a device that operates at the data link layer (Layer 2) of the OSI model. It is responsible for forwarding frames based on the MAC addresses of the source and destination devices. A switch can also perform media access control, VLAN tagging, QoS, and other Layer 2 functions. A router, on the other hand, operates at the network layer (Layer 3) and routes packets based on their IP addresses. A transceiver is a device that converts electrical signals to optical signals and vice versa, and operates at the physical layer (Layer 1). A UTP cable is a type of twisted pair cable that is also used at the physical layer to transmit data. References: Data link layer - Wikipedia, Data Link Layer | Layer 2 | The OSI-Model, What is Layer 2? - Definition from Techopedia, An Overview of Layer 2 Ethernet – What is it and why does it matter?

 Switches and routers are both networking devices that operate at different layers of the OSI model and perform different functions. The key differences between L2 switches and routers are:

• Switches operate at the data link layer (Layer 2) of the OSI model, while routers operate at the network layer (Layer 3). This means that switches forward frames based on the MAC addresses of the source and destination devices, while routers route packets based on the IP addresses of the source and destination networks.
• Switches build a MAC table that maps MAC addresses to switch ports, while routers build a routing table that maps IP addresses to next-hop interfaces. The MAC table is used by switches to determine which port to send a frame to, while the routing table is used by routers to determine which interface to send a packet to.
• Switches offer a considerably higher port density than routers, meaning that they can connect more devices to the network. Switches typically have dozens or hundreds of Ethernet ports, while routers usually have a few Ethernet ports and other types of ports such as ADSL, cable, fiber, dial-up, etc. Switches are used to create LAN segments, while routers are used to connect different networks or subnets.
• Switches are faster than routers because they do not take up time looking at the network layer header information. Switches can forward frames at wire speed, while routers need to process packets at the network layer and perform additional functions such as NAT, firewall, QoS, etc.

References: Switch (L2/L3) Vs Router: Comparison and Differences in TCP/IP Networks, Key Differences Between Routers and Different Types of Switches, Layer 2 Switch - How it operates, when to use it - Network Encyclopedia, Layer 2 switching - Study-CCNA, Differences Between Layer 2 and Layer 3 Switches｜Which one do you need？

The 051 Model is a reference model that describes how data communications occur on a network using five layers: physical, data link, network, transport, and application. The 051 Model is based on the OSI Model, which has seven layers, but it simplifies the presentation and session layers into the application layer. The 051 Model is used to understand the functions and interactions of different network components, such as devices, protocols, and services. Each layer of the 051 Model has a specific role and responsibility in the data communication process, as follows:

• The physical layer defines the electrical and mechanical characteristics of the transmission medium, such as cables, connectors, and signals. It also determines how data is encoded into bits and transmitted over the medium.
• The data link layer defines the rules and methods for accessing and sharing the transmission medium among multiple devices. It also provides error detection and correction mechanisms to ensure reliable data delivery.
• The network layer defines the logical addressing and routing schemes for data packets across different networks. It also provides congestion control and fragmentation/reassembly functions to optimize network performance.
• The transport layer defines the end-to-end communication and reliability services for data segments between applications. It also provides flow control and multiplexing/demultiplexing functions to manage data streams.
• The application layer defines the protocols and services that enable user applications to exchange data over the network. It also provides functions such as encryption, authentication, and compression to enhance data security and efficiency.

References:

• 051 Model
• OSI Model
• Network Fundamentals

 The header in the exhibit belongs to the Internet Protocol version 4 (IPv4), which is the most widely used protocol for routing and delivering packets across networks. IPv4 is a connectionless and unreliable protocol that operates at the network layer of the OSI model. The IPv4 header consists of 20 bytes (160 bits) of fixed fields and up to 40 bytes (320 bits) of optional fields. The fixed fields include:

• Version: 4 bits that indicate the version of the IP protocol, which is 4 for IPv4.
• IHL (Internet Header Length): 4 bits that indicate the length of the IP header in 32-bit words, which is 5 for the minimum header size of 20 bytes.
• Type of Service: 8 bits that indicate the quality of service (QoS) parameters for the packet, such as precedence, delay, throughput, and reliability.
• Total Length: 16 bits that indicate the total length of the IP packet in bytes, including the header and the data.The maximum value is 65535 bytes.
• Identification: 16 bits that identify the packet for fragmentation and reassembly purposes.
• Flags: 3 bits that control the fragmentation of the packet. The first bit is reserved and must be zero. The second bit is the Don’t Fragment (DF) bit, which indicates whether the packet can be fragmented or not. The third bit is the More Fragments (MF) bit, which indicates whether the packet is the last fragment or not.
• Fragment Offset: 13 bits that indicate the position of the fragment in the original packet, measured in units of 8 bytes.
• TTL (Time To Live): 8 bits that indicate the maximum number of hops that the packet can traverse before being discarded. The TTL is decremented by one at each hop, and the packet is dropped if the TTL reaches zero.
• Protocol: 8 bits that indicate the protocol of the data carried in the packet, such as TCP, UDP, ICMP, etc. The protocol numbers are defined in the List of IP protocol numbers.
• Header Checksum: 16 bits that provide error detection for the IP header. The checksum is calculated by adding the 16-bit words of the header and taking the one’s complement of the result.The checksum is recomputed and verified at each hop.
• Source IP Address: 32 bits that indicate the IP address of the sender of the packet.
• Destination IP Address: 32 bits that indicate the IP address of the receiver of the packet.
• Options: Variable-length field that contains optional information for the IP packet, such as security, routing, timestamp, etc. The options are padded with zeros to make the header length a multiple of 32 bits.

The IPv4 header can be distinguished from other protocol headers by the value of the Version field, which is 4 for IPv4. Other protocol headers have different values for the Version field or do not have a Version field at all. For example, the IPv6 header has a Version field of 6, the UDP header does not have a Version field, the Ethernet header has a Type field instead of a Version field, and the TCP header has a Data Offset field instead of a Version field. References:

• Aruba Certified Network Technician (ACNT) | HPE Aruba Networking
• Aruba Documentation Portal
• Introduction and IPv4 Datagram Header - GeeksforGeeks
• Protocol header - Oxford Reference
• List of IP protocol numbers - Wikipedia

The PCs are not able to successfully establish bidirectional communication because they are on different subnets and their default gateways are not configured correctly. The default gateway is the IP address of the router interface that connects to the same subnet as the PC. The default gateway allows the PC to send packets to destinations outside its own subnet. In this case, PC-1 and PC-2 are on the 172.16.30.0/24 and 172.16.31.0/24 subnets respectively, and the router interfaces are 172.16.30.254 and 172.16.31.254 respectively. Therefore, the correct default gateway for PC-1 is 172.16.30.254 and the correct default gateway for PC-2 is 172.16.31.254. Changing PC-2’s default gateway to 172.16.31.254 will enable the communication between PC-1 and PC-212 References:

• Aruba Certified Network Technician (ACNT) - HPE Certification and Learning
• Aruba Certified Network Technician (ACNT) - Aruba Networks.

The end command is used to exit from any configuration context and return to the manager context. The manager context is indicated by the # symbol at the end of the prompt. The manager context allows you to execute commands that do not require saving changes to the configuration, such as show or clear commands. The disable command is used to exit from the manager context and return to the operator context, which is indicated by the > symbol. The quit and exit commands are used to exit from the current context and return to the parent context, such as from config-if to config. However, these commands do not move you directly to the manager context from any configuration context. Therefore, the correct answer is A. end. References: Navigating to the manager context (#) - Aruba, Manager context (#) - Aruba