18) Explaining Disaster Recovery and High Availability Concepts Flashcards
A network consultant is looking for a device that will serve as a temporary power source in the event of a blackout. What is the name of this device?
A. UPS
B. MTBF
C. MTTR
D. PDU
A. UPS (uninterruptible power supply)
At the system level, an uninterruptible power supply (UPS) will provide a temporary power source in the event of a blackout. UPS runtime may range from a few minutes for a desktop-rated model to hours for an enterprise system.
Mean time between failures (MTBF) represents the expected lifetime of a product. The calculation for MTBF is the total operational time divided by the number of failures.
Mean time to repair (MTTR) measures the time to correct a fault and restore the system to full operation. This can also include the mean time to replace or recover. MTTR is the total number of hours of unplanned maintenance divided by the number of failure incidents.
A power distribution unit (PDU) has circuitry to “clean” the power signal. It also provides protection against spikes, surges, and brownouts and can integrate with an uninterruptible power supply (UPS).
While evaluating load balancers, a network engineer needs to acquire a switch that can handle complex logic. Which switch would the engineer use for this requirement?
A. Layer 4 Switch
B. Layer 7 Switch
C. Bridge
D. Layer 2 Switch
B. Layer 7 Switch
Layer 7 switch —As web applications have become more complex, modern load balancers need to make forwarding decisions based on application-level data. This requires more complex logic, but the processing power of modern appliances is sufficient.
Layer 4 switch—Basic load balancers make forwarding decisions on IP address and TCP/UDP header values, working at the transport layer of the OSI model.
An Ethernet bridge works at the data link layer (layer 2) to establish separate physical network segments while keeping all nodes in the same logical network.
An Ethernet layer 2 switch performs the same sort of function as a bridge, but in a more granular way and for many more ports than are supported by bridges.
A network engineer decides that the organization needs to purchase a device that “cleans” the power signal, provides protection against spikes, surges, and brownouts, and can integrate with an uninterruptible power supply (UPS). What is the name of this device?
A. MTTF
B. MTBF
C. MTTR
D. PDU
D. PDU - Power Distribution Unit
A power distribution unit (PDU) has circuitry to “clean” the power signal. It also provides protection against spikes, surges, and brownouts and can integrate with an uninterruptible power supply (UPS).
Mean Time to Failure (MTTF) expresses a similar metric as MTBF, however, for non-repairable components.
Mean Time Between Failures (MTBF) represents the expected lifetime of a product. The calculation for MTBF is the total operational time divided by the number of failures.
Mean Time to Repair (MTTR) measures the time to correct a fault and restore the system to full operation. This can also include the mean time to replace or recover. MTTR is the total number of hours of unplanned maintenance divided by the number of failure incidents.
A network contractor evaluates a protocol that allows multiple physical routers to serve as a single default gateway for a subnet. What is the name of this protocol?
A. Virtual IP
B. Hot Standby Router
C. Multipathing
D. Diverse Paths
B. Hot Standby Router
Cisco’s proprietary Hot Standby Router Protocol (HSRP) allows multiple physical routers to serve as a single default gateway for a subnet. Each router must have an interface connected to the subnet, with its own unique MAC address and IP address.
A virtual IP or shared or floating address uses a public IP to access the service shared between the two instances in the cluster, unlike load balancing with a single appliance.
Multipathing means that a network node has more than one physical link to another node.
Diverse paths refer to provisioning links over separate cable conduits that are physically distant from one another.
A network specialist wants to provision two load balancer appliances so that if one fails, the other can still handle client connections. What type of load balancer distribution method should the network specialist use?
A. Virtual IP
B. Clustering
C. Multipathing
D. Diverse Paths
A. Virtual IP
A virtual IP or shared or floating address uses a public IP to access the service shared between the two instances in the cluster, unlike load balancing with a single appliance. This allows the network specialist to provision two load balancer appliances. If one fails, the other can still handle client connections.
Where a load balancer distributes traffic between independent processing nodes, clustering allows multiple redundant processing nodes that share data to accept connections.
Multipathing means that a network node has more than one physical link to another node.
Diverse paths refer to provisioning links over separate cable conduits that are physically distant from one another.
A network technician needs to install a load balancer onto the network as the department has experienced issues with streaming media servers. What switches could the technician use to support this request? (Select all that apply.)
A. Bridge
B. Layer 4 Switch
C. Layer 2 Switch
D. Layer 7 Switch
B. Layer 4 Switch
D. Layer 7 Switch
Layer 4 switch—Basic load balancers make forwarding decisions on IP address and TCP/UDP header values, working at the transport layer of the OSI model.
Layer 7 switch (content switch)—As web applications have become more complex, modern load balancers need to make forwarding decisions based on application-level data.
An Ethernet bridge works at the data link layer (layer 2) to establish separate physical network segments while keeping all nodes in the same logical network.
An Ethernet layer 2 switch performs the same sort of function as a bridge, but in a more granular way and for many more ports than are supported by bridges. Each switch port is a separate collision domain.
A network contractor reviews key performance indicators regarding the time taken to correct a fault and restore the system to full operation. What is the name of this process?
A. MTTF
B. MTBF
C. MTTR
D. PDU
C. MTTR - Mean Time to Repair
Mean Time to Repair (MTTR) measures the time to correct a fault and restore the system to full operation. This can also include the mean time to replace or recover. MTTR is the total number of hours of unplanned maintenance divided by the number of failure incidents.
Mean Time to Failure (MTTF) expresses a similar metric as MTBF, however, for non-repairable components.
Mean Time Between Failures (MTBF) represents the expected lifetime of a product. The calculation for MTBF is the total operational time divided by the number of failures.
A power distribution unit (PDU) has circuitry to “clean” the power signal. It also provides protection against spikes, surges, and brownouts and can integrate with an uninterruptible power supply (UPS).
A network specialist analyzes the key performance indicators associated with the component reliability regarding the expected lifetime of repairable products. What reliability analysis is the network specialist conducting?
A. MTTF
B. MTBF
C. MTTR
D. PDU
B. MTBF - Mean Time Between Failures
Mean Time Between Failures (MTBF) represents the expected lifetime of a product. The calculation for MTBF is the total operational time divided by the number of failures.
Mean Time to Failure (MTTF) expresses a similar metric as MTBF, however, for non-repairable components.
Mean Time to Repair (MTTR) measures the time to correct a fault and restore the system to full operation.
A power distribution unit has circuitry to “clean” the power signal, provides protection against spikes, surges, and brownouts, and can integrate with an uninterruptible power supply (UPS).
A network engineer deploys a hardware appliance to distribute client requests across server nodes in a farm or pool. What is the name of this appliance?
A. Load Balancer
B. Virtual IP
C. Hot Standby Router
D. Multipathing
A. Load Balancer
A load balancer can be deployed as a hardware appliance or software instance to distribute client requests across server nodes in a farm or pool. A network engineer can also use a load balancer in any situation with multiple servers providing the same function.
A virtual IP or shared or floating address uses a public IP to access the service shared between the two instances in the cluster, unlike load balancing with a single appliance. This allows the network specialist to provision two load balancer appliances.
Multipathing means that a network node has more than one physical link to another node.
A hot standby router monitors the status of the active router and takes over the role if the active router becomes unavailable, also triggering the selection of a new standby router from the remaining routers in the group.
A network technician confirms that the server room has adequate environmental controls to mitigate the loss of availability through mechanical issues with equipment, such as overheating. What service provides environmental control in the room?
A. UPS
B. HVAC
C. MTTR
D. PDU
B. HVAC (Heating, Ventilation, Air Conditioning)
Environmental controls mitigate the loss of availability through mechanical issues with equipment, such as overheating. Building control systems maintain an optimum working environment for different parts of the building. The acronym HVAC (Heating, Ventilation, Air Conditioning) describes these services.
At the system level, an uninterruptible power supply (UPS) will provide a temporary power source in the event of a blackout.
Mean time to repair (MTTR) measures the time to correct a fault and restore the system to full operation.
A power distribution unit (PDU) has circuitry to “clean” the power signal. It also provides protection against spikes, surges, and brownouts and can integrate with an uninterruptible power supply (UPS).
