HPE6-A85 Exam Dumps - HP Certification Questions and Answers

USE CASE: a) Controls the dynamic addition and removal of ports to groups Technology: 3) LACP

USE CASE: b) Tags Ethernet frames with an additional VLAN header Technology: 1) 802.1Q

USE CASE: c) Used to authenticate EAP-Capable client on a switch port Technology: 2) 802.1X

USE CASE: d) Used to identify a voice VLAN to an IP phone Technology: 4) LLDP

The following table summarizes the switching technologies and their use cases:

Technology

Use case

1) 802.1Q

802.1Q is a standard that defines how to create and manage virtual LANs (VLANs) on a network. VLANs allow network administrators to logically segment a network into different broadcast domains, improving security, performance, and manageability. 802.1Q tags Ethernet frames with an additional VLAN header that contains a VLAN identifier (VID), which indicates which VLAN the frame belongs to1.

2) 802.1X

802.1X is a standard that defines how to provide port-based network access control (PNAC) on a network. PNAC allows network administrators to authenticate and authorize devices before granting them access to network resources. 802.1X uses the Extensible Authentication Protocol (EAP) to exchange authentication messages between a supplicant (a device that wants to access the network), an authenticator (a device that controls access to the network, such as a switch), and an authentication server (a device that verifies the credentials of the supplicant, such as a RADIUS server)2.

3) LACP

LACP stands for Link Aggregation Control Protocol, which is part of the IEEE 802.3ad standard that defines how to bundle multiple physical links into a single logical link, also known as a link aggregation group (LAG) or an EtherChannel. LAGs provide increased bandwidth, load balancing, and redundancy for network connections. LACP controls the dynamic addition and removal of ports to groups, ensuring that only ports with compatible configurations can form a LAG3.

4) LLDP

LLDP stands for Link Layer Discovery Protocol, which is part of the IEEE 802.1AB standard that defines how to discover and advertise information about neighboring devices on a network. LLDP operates at Layer 2 of the OSI model and uses TLVs (type-length-value) to exchange information such as device name, port number, VLAN ID, capabilities, and power requirements. LLDP can be used to identify a voice VLAN to an IP phone by sending a TLV that contains the voice VLAN ID and priority.

References: 1 https://en.wikipedia.org/wiki/IEEE_802.1Q  2 https://en.wikipedia.org/wiki/IEEE_802.1X  3 https://en.wikipedia.org/wiki/Link_aggregation https://en.wikipedia.org/wiki/Link_Layer_Discovery_Protocol

When a client roams from one access point to another, it must change the destination MAC address on its 802.11 frames to match the new access point to which it is associated. The SSID does not change since it is typically consistent across an entire WLAN, and the default gateway remains the same as long as the client stays within the same IP subnet. The association to a new access point involves updating the destination MAC address in the frames that the client sends.

Using the provided topology and show command output, it can be determined that L3-SW-2 in the Branch Office does not have a route to reach the subnet where PC1 resides (192.168.1.0/24 in the HQ Office). L3-SW-1 in the HQ Office has a route to the Branch Office subnet (172.16.1.0/24), but without the reciprocal route on L3-SW-2, traffic from the Branch Office will not be able to reach the HQ Office subnet, hence PC1 cannot ping PC2.

The main characteristic of the 6 GHz band that is true among the given options is that in North America, the 6 GHz band offers more 80 MHz channels than there are 40 MHz channels in the 5 GHz band. This characteristic provides more spectrum availability, less interference, and higher throughput for wireless devices that support Wi-Fi 6E Wi-Fi Enhanced (Wi-Fi 6E) is an extension of Wi-Fi 6 (802.11ax) standard that operates in the newly available unlicensed frequency spectrum around 6 GHz in addition to existing bands below it. Some facts about this characteristic are:

In North America, there are up to seven non-overlapping channels available in each of three channel widths (20 MHz, 40 MHz, and 80 MHz) in the entireunlicensed portion of the new spectrum (5925–7125 MHz). This means there are up to 21 non-overlapping channels available for Wi-Fi devices in total.

In comparison, in North America, there are only nine non-overlapping channels available in each of two channel widths (20 MHz and 40 MHz) in the entire unlicensed portion of the existing spectrum below it (2400–2483 MHz and 5150–5825 MHz). This means there are only up to nine non-overlapping channels available for Wi-Fi devices in total.

Therefore, in North America, there are more than twice as many non-overlapping channels available in each channel width in the new spectrum than in the existing spectrum below it.

Specifically, there are more than twice as many non-overlapping channels available at 80 MHz width (seven) than at 40 MHz width (three) in the existing spectrum below it.

The other options are not true because:

Less RF signal is absorbed by objects in a 6 GHz WLAN: This option is false because higher frequency signals tend to be more absorbed by objects than lower frequency signals due to higher attenuation Attenuation is a general term that refers to any reduction in signal strength during transmission over distance or through an object or medium . Therefore, RF signals in a 6 GHz WLAN would be more absorbed by objects than RF signals in a lower frequency WLAN.

The 6 GHz band is fully backward compatible with existing bands: This option is false because Wi-Fi devices need to support Wi-Fi 6E standard to operate in the new spectrum around 6 GHz . Existing Wi-Fi devices that do not support Wi-Fi 6E standard cannot use this spectrum and can only operate in existing bands below it.

Low Power Devices are allowed for indoor and outdoor usage: This option is false because Low Power Indoor Devices (LPI) are only allowed for indoor usage under certain power limits and registration requirements . Outdoor usage of LPI devices is prohibited by regulatory authorities such as FCC Federal Communications Commission (FCC) is an independent agency of United States government that regulates communications by radio, television, wire, satellite, and cable across United States . However, outdoor usage of Very Low Power Devices (VLP) may be allowed under certain power limits and without registration requirements.

References: https://www.wi-fi.org/discover-wi-fi/wi-fi-certified-6e https://www.wi-fi.org/file/wi-fi-alliance-spectrum-needs-study https://www.cisco.com/c/en/us/products/collateral/wireless/spectrum-expert-wi-fi/prod_white_paper0900aecd807395a9.html https://www.cisco.com/c/en/us/support/docs/wireless-mobility/wireless-lan-wlan/82068-power-levels.html https://www.wi-fi.org/file/wi-fi-alliance-unlicensed-spectrum-in-the-us

An AP signal strength of .0000001 milliwatts is equivalent to -80 dBm. The dBm scale is logarithmic, with every 10 dBm representing a tenfold increase or decrease in power. A signal strength of 1 milliwatt (mW) is 0 dBm, so a signal strength of .0000001 mW is 80 decibels less than 1 mW, which is -80 dBm.

The Aruba CX 6300 Series is an ideal access switch for medium to high-density client environments, offering a range of models that can accommodate various port densities and types. For a distribution rack supporting 200-380 clients, printers, and APs, the CX 6300 provides the necessary port density and performance capabilities, including high-speed uplinks, support for Class 4 PoE (PoE+), and stacking capabilities. This series is cost-effective and designed for enterprises requiring reliable connectivity and consistent performance. The other options, such as the CX 6400, CX 6200, and CX 6000, may either be over-specified and more expensive (CX 6400), not offer the necessary port density (CX 6200), or not exist in the product line (CX 6000).

The advantage of Layer 2 MAC authentication is that it does not require any setup or configuration on the client device. The network devices (like switches or access points) perform the authentication automatically based on the MAC address of the device when it tries to connect to the network.

QoS Quality of Service (QoS) is a set of techniques that manage network resources and provide different levels of service to different types of traffic based on their requirements. QoS can improve network performance, reduce latency, increase throughput, and prevent congestion. concept and its definition. Here is my answer:

QoS Concept:

Best Effort Service

Class of Service

Differentiated Services

WMM ====================== Definition:

d) A method where traffic is treated equally in a first-come, first-served manner a) A method for classifying network traffic at Layer 2 by marking 802.1Q VLAN Ethernet frames with one of eight service classes b) A method for classifying network traffic at Layer 3 by marking packets with one of 64 different service classes c) A method for classifying network traffic using access categories based on the IEEE 802.11e QoS standard

Short But Comprehensive Explanation of Correct Answer Only: The correct match between QoS concept and its definition is as follows:

Best Effort Service: This is a method where traffic is treated equally in a first-come, first-served manner without any prioritization or differentiation. This is the default service level for most networks and applications that do not have specific QoS requirements or guarantees. Best Effort Service does not provide any assurance of bandwidth, delay, jitter, or packet loss.

Class of Service: This is a method for classifying network traffic at Layer 2 by marking 802.1Q VLAN Ethernet frames with one of eight service classes (0 to 7). These service classes are also known as IEEE 802.1p priority values or PCP Priority Code Point (PCP) is a 3-bit field in the 802.1Q VLAN tag that indicates the priority level of an Ethernet frame . Class of Service allows network devices to identify and handle different types of traffic based on their priority levels. Class of Service is typically used in LAN Local Area Network (LAN) is a network that connects devices within a limited geographic area, such as a home, office, or building environments where Layer 2 switching is predominant.

Differentiated Services: This is a method for classifying network traffic at Layer 3 by marking packets with one of 64 different service classes (0 to 63). These service classes are also known as DiffServ Code Points (DSCP) DiffServ Code Point (DSCP) is a 6-bit field in the IP header that indicates the service class of a packet . Differentiated Services allows network devices to identify and handle different types of traffic based on their service classes. Differentiated Services is typically used in WAN Wide Area Network (WAN) is a network that connects devices across a large geographic area, such as a country or continent environments where Layer 3 routing is predominant.

WMM: This is a method for classifying network traffic using access categories based on the IEEE 802.11e QoS standard. WMM stands for Wi-Fi Multimedia and it is a certification program developed by the Wi-Fi Alliance to enhance QoS for wireless networks. WMM defines four access categories (AC): Voice, Video, Best Effort, and Background. These access categories correspond to different priority levels and contention parameters for wireless traffic. WMM allows wireless devices to identify and handle different types of traffic based on their access categories.

References: https://en.wikipedia.org/wiki/Quality_of_service https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/qos_dfsrv/configuration/xe-16/qos-dfsrv-xe-16-book/qos-dfsrv-overview.html https://www.cisco.com/c/en/us/support/docs/quality-of-service-qos/qos-packet-marking/10103-dscpvalues.html https://www.cisco.com/c/en/us/support/docs/wireless-mobility/wireless-lan-wlan/81831-qos-wlan.html https://www.wi-fi.org/discover-wi-fi/wi-fi-certified-wmm

TCP 3-Way Handshake sequence is:

Step 1: The initiating host sends a packet with no data to the target host with a SEQ=1 and sets the SYN flag to 1.

Step 2: The target host responds with a packet with ACK=2, SEQ=8, and the SYN and ACK flags set to 1.

Step 3: The initiating host sends a packet with SEQ=2, ACK=9, and the ACK flag set to 1.

Step 4: A normal-controlled connection is established.

References: https://en.wikipedia.org/wiki/Transmission_Control_Protocol https://www.cisco.com/c/en/us/support/docs/ip/routing-information-protocol-rip/13788-3.html

A static route is a route that is manually configured on a router or switch and does not change unless it is modified by an administrator. Static routes are used to specify how traffic should reach specific destinations that are not directly connected to the device or that are not reachable by dynamic routing protocols. In Aruba CX switches, static routes can be configured using the ip route command in global configuration mode. Based on the “show ip route” output on an Aruba CX 8400 switch, the route “10.1 20 0/24, vrf default via 10.1.12.2, [1/0]” is a static route because it has an administrative distance of 1 and a metric of 0, which are typical values for static routes. References: https://en.wikipedia.org/wiki/Static_routing https://www.arubanetworks.com/techdocs/AOS-CX_10_04/NOSCG/Content/cx-noscg/ip-routing/static-routes.htm https://www.arubanetworks.com/techdocs/AOS-CX_10_04/NOSCG/Content/cx-noscg/ip-routing/show-ip-route.htm