Chapter 8
The backbone architecture layer that is closest to the users is the Access layer Distribution layer Core layer Privacy layer Switched layer
Access layer
Which of the following is not true about multiswitch VLANs? Several switches are used to build a VLAN The switches in the VLAN can send packets among themselves in a way that identifies the VLAN to which the packet belongs. In some multi-switch VLANs, the Ethernet packet is modified based on the emerging IEEE 802.1q standard. In some multi-switch VLANs, a new VLAN packet encapsulates the Ethernet packet. All of the above are true statements.
All of the above are true statements.
The _________ is the part of the backbone that connects the different backbones together. Access layer Distribution layer Core layer Privacy layer Switched layer
Core layer
The _______ is the part of the backbone that connects the LANs together. Access layer Distribution layer Core layer Privacy layer Switched layer
Distribution layer
A VLAN network assigns computers to LAN segments by hardware. True False
False
A VLAN requires the computer manager to reconfigure the physical cables to the switch if a computer is moved from one port to another port on a switch. True False
False
A backbone network that connects many backbone networks spanning several buildings at a single location is often called an Internet backbone. True False
False
A hardware device that operates at the application layer is a router. True False
False
A switched backbone uses a bus topology True False
False
Backbone networks typically use lower speed circuits to interconnect a series of LANs and provide connections to other backbone networks. True False
False
Layer-3 switches switch messages based on their data link layer address. True False
False
One advantage of a routed backbone is that is requires little management. True False
False
Routed backbones use switches that move packets based on data link layer addresses. True False
False
Routers can only connect the same type of cable. True False
False
Routers operate at the application layer. True False
False
The cable to connect BNs is usually twisted pair. True False
False
VLANs prioritize traffic based on the ______. IEEE 802.1q standard IEEE 802.11 standard VLAN size multiswitch allocation switch dynamics
IEEE 802.1q standard
Using ______ capabilities, network managers can connect VOIP phones directly into a VLAN switch and configure the switch to reserve sufficient network capacity so that they will always be able to send and receive voice messages. backbone switched routed QoS access
QoS
A subnetted or hierarchical backbone can also be called: Bridged backbone Virtual LAN Hubbed backbone Collapsed backbone Routed backbone
Routed backbone
________ move packets along the backbone based on their network layer address. Bridged backbones Hubbed backbones Multistation access unit backbones Routed backbones NIC backbones
Routed backbones
A __________ type of BN has a star topology with one device, such as a switch, at its center. Bridged backbone Virtual LAN Hubbed backbone Switched backbone Routed backbone
Switched backbone
_________ have no backbone cable. Switched backbones Cloud routed backbones Hubbed backbones Bridged backbones Multistation access unit backbones
Switched backbones
Which of the following is not true about Layer-3 switches? They switch messages based on their IP address. They can be used in place of routers. They function faster than routers. They have more simultaneously active ports than routers. They can only switch messages based on their data link layer addresses.
They can only switch messages based on their data link layer addresses.
Which of the following is true regarding switched backbones? They place all network devices for one part of the building physically in the same room, often in a rack of equipment They have an advantage of requiring less cable They make it more difficult to move computers from one LAN to another Network capacity is always tied to the physical location of the computers They are harder to maintain and upgrade than a BN that is not rack-based
They place all network devices for one part of the building physically in the same room, often in a rack of equipment
Which of the following is not true about backbone networks? They may also be called enterprise networks if they connect all networks within an organization. They typically connect many networks, including LANs. They typically provide connections to other BNs, WANs, MANs, and the Internet. They may also be called campus networks if they connect many BNs spanning several buildings as a single location. They tend to use lower speed circuits than LANs.
They tend to use lower speed circuits than LANs.
A backbone network is a high-speed network that connects many networks True False
True
A key advantage of a chassis switch is its flexibility. True False
True
A room that contains a rack of equipment for a rack-based collapsed backbone is also called the main distribution facility (MDF) or central distribution facility (CDF). True False
True
A routed backbone tends to be used more for large networks than VLANs, although VLAN high speed switches and this new type of LAN-BN architecture are now being considered. True False
True
One basic component of a backbone network is the hardware device that connects other networks to the backbone. True False
True
One difference between a switch and a router is that a router will only process messages addressed to the router, while a switch processes all messages. True False
True
Routers connect two or more network segments that use the same or different data link protocols, but the same network protocol. True False
True
Routers use network layer address to forward packets between network segments. True False
True
Switches and routers are devices that can connect networks to the BN. True False
True
The distribution layer of a backbone connects LANs together. True False
True
The primary advantage of a routed backbone is that it clearly segments each part of the network connected to the backbone because each segment has its own subnet addresses that can be managed separately. True False
True
VLANs provide faster performance compared to switched, collapsed or routed backbone architectures. True False
True
A _____________ type of BN is a new type of LAN/BN architecture made possible by intelligent, high speed switches that assign computers to LAN segments via software, rather than by hardware. Bridged backbone Virtual LAN Hubbed backbone Collapsed backbone Routed backbone
Virtual LAN
Which of the following is a fundamental backbone network architecture? Bridged backbone Virtual LAN Hubbed backbone Gatewayed backbone Virtual backbone
Virtual LAN
Which of the following would be least effective in improving backbone performance? improving the computers in the network changing the demand placed on the network adding new keyboards to the client computers upgrading the circuits between computers improving devices in the network
adding new keyboards to the client computers
Which of the following would not be part of an "ideal" backbone design for the future? access layer composed of 10/100 layer 2 Ethernet switches distribution layer composed of layer 3 Ethernet switches of 100 (or 1000) Base-T redundant switches core layer composed of layer 3 Ethernet switches running 10 (or 40) GbE over fiber coax cabling throughout LANs and BN
coax cabling throughout LANs and BN
The biggest drawbacks to VLANs are their_________________. cost and management complexity size and contention contention and cost learning curve and contention speed and size
cost and management complexity
Which of the following is not a technology layer that is considered when designing backbone networks? access layer distribution layer decentralized layer core layer none of the options
decentralized layer
Which of the following is not a type of hardware device that can be used to interconnect networks? layer 3 switches routers dumb terminals layer 2 switches all of the above can be used
dumb terminals
Network demand will not be reduced by: restricting (or moving) applications such as desktop videoconferencing using network devices to ensure that broadcast messages do not go to other networks encouraging the use of applications such as medical imaging sending status information to all computers on all LANs in the backbone network restricting (or moving) applications such as multimedia
encouraging the use of applications such as medical imaging
Circuit capacity on a backbone network will not be improved by: going from 100Base-T Ethernet to 10Base-T Ethernet going from 100Base-T Ethernet to gigabit Ethernet adding additional circuits alongside heavily used ones replacing a shared circuit backbone with a switched circuit backbone providing a faster circuit to the server
going from 100Base-T Ethernet to 10Base-T Ethernet
Switches: learn addresses by reading the source and destination addresses operate at the physical layer only connect two ore more network segments that use different data link protocols connect two or more network segments that use different network protocols have become more popular than layer 2 switches
learn addresses by reading the source and destination addresses
Associated with a switched backbone, MDF is an acronym for: multi-station device foundation main distribution facility manual data frequency multiplexer downstream flow maximum data facility
main distribution facility
Routers: operate at the application layer operate only at the physical layer cannot connect two or more networks that use the same type of cable may also be called TCP/IP gateways operate only at the data link layer
may also be called TCP/IP gateways
Devices in a rack are connected together using ___________. patch cables string servers modules chassis switches
patch cables
Computers can be assigned to a VLAN based on the ________. IEEE 802.1q standard NIC interface physical port on the switch IEEE 802.3 standard physical location of the computer
physical port on the switch
With a switched backbone network, the equipment is usually placed in a ______. server NIC cabinet basement rack
rack
Routers: require more management than switches are not susceptible to time delays use data link layer addresses to move packets that leave the subnet require only a few set of TCP/IP addresses don't need much time to establish separate subnet addresses for each LAN
require more management than switches
A _____________ type of BN segments (each of which has a special set of subnet addresses that can be managed by different network managers) each part of the network connected to the backbone. bridged backbone virtual LAN hubbed backbone collapsed backbone routed backbone
routed backbone
Which of the following is not a way that a router differs from a switch? routers can connect two or more networks that use the same data link protocol routers only process messages that are specifically addressed to it routers operate at the network layer routers perform more processing on each message than switch routers can choose the "best" route between networks for forwarding a packet
routers can connect two or more networks that use the same data link protocol
Most backbone devices are store-and-forward devices. One simple way to improve performance is to ensure that they have ________________. enough ports sufficient memory twisted pair connections large wheels IEEE 802.11
sufficient memory
Which of the following is not true about switched backbones? performance is improved over traditional (bridged or routed) backbone networks each connection into the switch is a separate point-to-point circuit which supports simultaneous access by the LANs connected to the switch there are many more networking devices in a switched backbone network if the switch fails, so does the entire backbone network the backbone essentially exists in the switch; there is no backbone cable
there are many more networking devices in a switched backbone network
Device performance on a backbone network will not be improved by: using the same protocols in the backbone and the LANs using static routing in low to moderate traffic conditions ensuring that backbone devices have sufficient memory so that packets do not have to be retransmitted by the sender translating packets from one protocol to another as they enter the BN none of the options
translating packets from one protocol to another as they enter the BN
Switched backbone networks: always use a ring topology are the least common type of BN used in one building use a star topology with one device, usually a switch have a great deal of cable in their backbones tend to have less cable, but more network devices
use a star topology with one device, usually a switch