What of these is not a layer of Cisco's three-tiered architecture for data centers? (pg. 584)

A. access/edge layer

B. application layer

C. core layer

D. distribution layer

The tier in data center architecture that acts as the primary connection between the data center's connectivity and the servers. (pg. 584)

A. distribution layer

B. intermediate distribution frame

C. access/edge layer

D. aggregation layer

C. The access/edge layer consists of the cables and the access switches closest to the systems.

The distribution layer and aggregation layer are the same thing, just different terms. It interconnects racks of servers and other rack-mounted gear through top-of-rack switching.

An intermediate distribution frame (IDF) serves as a wiring focal point for all of the devices on a floor.

The tier in data center architecture that provides a method to interconnect and distribute data to all the systems. (pg. 585)

A. access

B. distribution

C. aggregation

D. core

B. or C. The distribution layer (aka aggregation layer) acts as the connection between the access layer and the core layer.

The tier in data center architecture that ties together all the switches at the distribution layer and acts as the point of connection to the external connections, including the Internet. (pg. 585)

A. core layer

B. access layer

C. management layer

D. aggregation layer

A. core layer

The access layer acts as the primary connection between the data center connectivity and the servers.

The management layer is a part of software-define networks (SDN), not physical data center infrastructure.

The aggregation layer is another name for the distribution layer.

The movement of data into/out of and around the data center. (pg. 585)

A. distribution layer

B. traffic flow

C. north-south traffic

D. east-west traffic

C. North-south traffic is a form of traffic flow. Northbound traffic leaves the data center, and southbound traffic enters it.

East-west traffic is data that flows between systems within the same data center.

The distribution layer acts as the connection between the access and core layer in a server rack.

A pool of mass storage devices presented over a network as any number of logical disks. (pg. 587)

A. redundant array of independent disks (RAID)

B. data center

C. storage area network (SAN)

D. network attached storage (NAS)

C. The SAN connects individual systems to a centralized bank of mass storage.

A data center is where the SAN is usually kept.

RAID is a way to create a fault-tolerant storage system using multiple disks, but it's not exclusively used over a network or in data centers.

NAS refers to a generally much smaller dedicated network appliance that attaches to a network switch and is used for local backups and other personal duties.

An availability solution in which more than one connection or path between a server and storage area network (SAN) is maintained in order to ensure continued availability in the event that one connection goes down. (pg. 589)

A. virtual disk

B. redundant array of independent disks (RAID)

C. dedicated switches

D. multipathing

D. With multipathing, if one connection fails, the other continues to keep the server connected to the SAN.

A virtual disk is a block of space that acts just like a physical hard drive.

RAID is a way to create a fault-tolerant storage system using multiple disks, but it doesn't address the connection between a server and SAN.

Dedicated switches are located at the top of server racks and help keep cable runs short and well organized. They have nothing to do with the server-SAN connection.

Network architecture that uses a mesh network that removes the need for dedicated connections between the backbone switches. (pg. 590)

A. spine-and-leaf

B. east-west traffic

C. three-tier

D. software-defined networking (SDN)

A. In a spine-and-leaf architecture, every spine-switch connects to every leaf-switch in a two-tiered mesh network. This removes the need for dedicated connections between the spine backbone switches, because traffic moves seamlessly from spine to leaf to spine, regardless of how many spine or leaf switches are on the network.

The three-tier data center is the traditional model that is/was popular in data centers for decades.

East-west traffic refers to data that moves between systems within the data center. It doesn't define architecture though.

Spine-and-leaf architecture uses SDN, but isn't exclusively virtual.

The practice of ensuring high availability on many levels through the use of additional equipment and connection options. (pg. 592)

A. clustering

B. load balancing

C. multipathing

D. redundancy

D. With redundancy, if one device or connection goes down, another takes its place.  You put primary switches, routers, firewalls and other network gear in place, then have backup devices at the ready in the event the primary device fails.

Load balancing and clustering is different from redundancy in that multiple pieces of equipment are connected and working at the same time.

Multipathing is the concept of having multiple active connections
between critical devices.

What is failover? (pg. 592)

A. Fault tolerance where the lines out of your ISP follow diverse paths to other routers.

B. Making one device look like a single device to the user for redundancy purposes.

C. To share among two or more systems the effort to enable some process to work.

D. The ability for backup systems to detect when a master has failed and then to take over.

D. The ability for backup systems to detect when a master has failed and then to take over.

A. describes the use of path diversity in connections to the Internet.

B. describes the practice of clustering equipment.

C.  describes the practice of load balancing.

The placement of a rack should ___ in a server area. (pg. 593)

A. minimize the use of physical space

B. optimize the airflow

C. maximize connectivity

D. be nearest the power source

B. All racks should be placed so that components draw air in from a shared cool row and then exhaust hot air into a hot row.

Reference record of all the hardware and software currently in use in a data center. (pg. 600)

A. network baseline

B. site survey

C. baseline configuration

D. performance baseline

The baseline configuration also includes network topology and placement of devices in the organization.

The baseline configuration is a type of network baseline. A performance baseline examines throughput, bandwidth and the like.

A site survey informs wireless network design by mapping out the physical space to identify requirements, obstacles and sources of interference.