Domain 2: Infrastructure Flashcards
Which of the following is the U.S. standard for synchronous data transmissions that defines data rates designated by optical carrier levels, such as OC-3, OC-12, OC-48, and OC-192?
A. SDH
B. SONET
C. ISDN
D. ATM
B. SONET
The Synchronous Optical Networking (SONET) standard defines a base data transfer rate of 51.84 Mbps, which is multiplied at the various optical carrier levels. An OC-3 connection therefore runs 155.52 Mbps, an OC-12 at 622.08 Mbps and so forth. The Synchronous Digital Hierarchy (SDH) is the European equivalent of SONET. Integrated Services Digital Network (ISDN) is a service that combines voice and data services using the Public Switched Telephone Network (PSTN), and Asynchronous Transfer Mode (ATM) is cell-switched protocol defining a combined voice, data, and video service.
Ed has been hired by a company to upgrade its network infrastructure. The current network is 10 Mbps Ethernet running on Category 5 (CAT5) twisted pair cable. There are 100 computers on the network, all of which have 10/100/1000 multispeed network interface adapters. The computers are all connected to hubs. Users are complaining that the network is too slow and connections are sometimes dropped. Management wants to upgrade to the fastest Ethernet standard possible, using the existing cabling, and still keep costs to a minimum. Which of the following implementations should Ed recommend to the client?
A. Upgrade to 100Base-TX and keep the existing hubs.
B. Upgrade to 1000Base-T and keep the existing hubs.
C. Upgrade to 100Base-FX and replace all of the hubs with switches.
D. Upgrade to 1000Base-T and replace all of the hubs with switches.
D. Upgrade to 1000Base-T and replace all of the hubs with switches.
The best solution in this scenario is to upgrade to 1000Base-T and replace the existing hubs with switches. 1000Base-T provides the fastest transfer speeds supported by the existing cable. Since users are complaining that the network is slow with the existing hubs, it makes sense to replace the shared hub environment with switches that offer dedicated bandwidth out each port. Any solution that does not replace the hubs would not address the users’ complaints. 100Base-TX would provide a speed increase, but it runs at one-tenth the speed of 1000Base-TX. Upgrading to 100Base-FX would require the cabling to be replaced with fiber optic, which would be very expensive.
Which of the following is a wide area networking mechanism that assigns labels to packets and forwards them based on those labels, rather than addresses?
A. Frame relay
B. MPLS
C. ATM
D. PPPoE
B. MPLS
Multiprotocol Label Switching (MPLS) is a data transfer mechanism that assigns labels to individual packets and then routes the packets based on those labels. Frame relay, Asynchronous Transfer Mode (ATM), and Point-to-Point Protocol over Ethernet (PPPoE) do not assign labels to packets.
On an unmanaged network, which of the following virtual networking components have media access control (MAC) addresses assigned to them?
A. Virtual switches
B. Virtual NICs
C. Hypervisors
D. Virtual firewalls
B. Virtual NICs
Just like physical network interface cards (NICs), virtual NICs have six-byte MAC addresses assigned to them, which enable them to be identified by data link layer protocols. Unlike physical NICs, however, it is typically an easy matter to modify a MAC address on a virtual NIC. Virtual switches, like physical switches, are not addressable devices, so they do not have MAC addresses on an unmanaged network. The hypervisor is the component on a host server that makes virtualization possible, so it does not require a MAC address. Virtual firewalls operate at the application layer, so they do not require data link layer MAC addresses. On a managed network, these devices have a MAC address to communicate with the management console, but addresses are not needed on an unmanaged network.
Alice’s company has 10 users who telecommute from home. They all have Integrated Services Digital Network Basic Rate Interface (ISDN BRI) configured and installed in their homes. They all need to transfer files between their homes and the corporate network. Each user connection has its two B channels combined for a total data transfer rate of 128 Kbps. Alice’s corporate network must be able to support all of these connections simultaneously. What service should Alice install at the corporate site, and how should she configure it to support the remote client connections?
A. Alice should install a single BRI connection and configure the access router to combine its B channels.
B. Alice should install five BRI connections and configure the access router to combine all ten B channels.
C. Alice should install multiple Primary Rate Interface (PRI) connections and configure the access router to combine all of the B channels.
D. Alice should install a single PRI connection and configure the access router to combine all 23 B channels.
D. Alice should install a single PRI connection and configure the access router to combine all 23 B channels.
In this scenario, there are 10 users with BRI connections, each of which has its two B channels combined to provide a 128 Kbps transfer rate per user. To support simultaneous connections to the corporate site, Alice will need to install and configure a single PRI link to support the aggregation of multiple B channel connections. A single PRI link has 23 B channels and 1 D channel. Therefore, the router can support up to 11 inbound BRI sessions simultaneously, which is more than enough. Installing a single BRI at the corporate site would not enable multiple simultaneous BRI connections, and installing five BRI links, for a total of ten 64 Kbps B channels, would not support the ten 128 Kbps sessions that are required. Installing multiple PRI links is unnecessary since the site only has to support ten inbound BRI connections.
Which of the following technologies do iSCSI initiators use to locate iSCSI targets on the network?
A. Active Directory
B. ICMP
C. DNS
D. iWINS
E. iSNS
E. iSNS
The Internet Storage Name Service (iSNS) is an application that provides iSCSI initiators with automated discovery of targets located on the network. iSNS can also function as a discovery service for Fibre Channel devices. Active Directory, Internet Control Message Protocol (ICMP), and Domain Name System (DNS) are not capable of registering iSCSI targets. iWINS does not exist.
At which layer of the Open Systems Interconnection (OSI) model do wireless range extenders operate?
A. Physical
B. Data link
C. Network
D. Transport
E. Session
F. Presentation
G. Application
A. Physical
Wireless range extenders are physical layer devices that receive signals from wireless access points and network adapters and retransmit them, enabling devices to connect that are farther apart than the network would normally support. Because the extenders do not process the packets in any way, but just retransmit the signals, they do not operate at any layer above the physical.
Ralph is installing an Ethernet local area network (LAN) for a small business with two offices on opposite sides of a courtyard. Ralph plans to run a multimode fiber-optic cable across the courtyard, but the budget is limited, and he can’t use fiber for the whole network. Therefore, he installs unshielded twisted pair (UTP) cable in the two offices, which have ten and twelve workstations, respectively. Which of the following devices should Ralph use to join the two UTP installations together into one LAN using the fiber-optic run across the courtyard, while keeping the cost to a minimum?
A. Media converters
B. Hubs
C. Switches
D. Routers
A. Media converters
Media converters will enable Ralph to join the multimode fiber-optic run to the UTP at both sides of the courtyard while maintaining a single network at minimum cost. Inexpensive small business hubs and switches cannot join different media together. Routers can join different media, but they are more expensive, and they would separate the installation into three separate networks.
A maintenance worker, while replacing a light fixture in an office building, accidentally severs a network cable in the drop ceiling. The tenants use a variety of local area network (LAN) technologies throughout the structure, but on that particular floor there are three separate LANs: a 10-node Thin Ethernet LAN using coaxial cable in a bus topology, a 25-node Gigabit Ethernet LAN using twisted pair cable in a star topology, and a 5-node Fiber Distributed Data Interface (FDDI) LAN using multimode fiber-optic cable in a double ring topology. Without knowing which of the LANs the severed cable belongs to, what is the maximum number of computers that could be directly affected by the cable break?
A. 0
B. 1
C. 5
D. 10
E. 25
F. 40
D. 10
The Thin Ethernet LAN is the network most endangered by the cable break. If a bus network is severed, all of the workstations on it are affected because the cable segments are no longer terminated at one end. The Gigabit Ethernet network uses a star topology, which means that only the one computer using the severed cable could be disconnected from the network. An FDDI double ring network can survive a single cable break without any workstations being affected.
Which of the following best describes the function of the network medium?
A. The network medium provides the physical connection between networked computers.
B. The network medium provides the protocol used to transmit data between end systems.
C. The network medium passes data between two routers.
D. The network medium processes electrical or light signals and converts them to data.
A. The network medium provides the physical connection between networked computers.
The network medium provides the physical connection between networked computers. This connection can be made through a copper-based, fiber-optic, or wireless medium. The network medium is not a protocol, and it does pass data; it only carries signals. The network medium does not process electrical or light pulses and convert them to data; it carries only the signals generated by transceivers.
Which of the following technologies can replace leased lines, such as T-1s, by multiplexing signals as packets switched through virtual circuits in a cloud?
A. E-1s
B. Frame relay
C. ATM
D. PPP
B. Frame relay
Frame relay is a packet switching service that uses a single leased line to replace multiple leased lines by multiplexing traffic through a cloud. The service can create virtual circuits connecting the subscriber’s network to multiple destinations, eliminating the need for a dedicated leased line to each remote site. An E-1 is the European equivalent to a T-1 leased line, which does not replace multiple T-1s. Asynchronous Transfer Mode (ATM) is a cell-switching WAN technology, and Point-to-Point Protocol (PPP) is a protocol that provides a data link layer connection between two end systems. Neither is a replacement for multiple T-1s.
Ralph, the administrator of a 500-node private internetwork, is devising a plan to connect the network to the Internet. The primary objective of the project is to provide all of the network users with access to web and email services while keeping the client computers safe from unauthorized users on the Internet. The secondary objectives of the project are to avoid having to manually configure IP addresses on each one of the client computers individually and to provide a means of monitoring and regulating the users’ access to the Internet. Ralph submits a proposal calling for the use of private IP addresses on the client computers and a series of proxy servers with public, registered IP addresses, connected to the Internet using multiple T-1 lines. Which of the following statements about Ralph’s proposed Internet access solution is true?
A. The proposal fails to satisfy both the primary and secondary objectives.
B. The proposal satisfies the primary objective but neither of the secondary objectives.
C. The proposal satisfies the primary objective and one of the secondary objectives.
D. The proposal satisfies the primary objective and both of the secondary objectives.
C. The proposal satisfies the primary objective and one of the secondary objectives.
Proxy servers provide network users with access to Internet services, and the unregistered IP addresses on the client computers protect them from unauthorized access by users on the Internet, which satisfies the first objective. The proxy servers also make it possible for network administrators to regulate users’ access to the Internet, which satisfies one of the two secondary objectives. However, the proxy servers cannot assign IP addresses to the client computers, and the plan makes no mention of DHCP or another automatic TCP/IP configuration mechanism. Therefore, the plan does not satisfy the other secondary objective.
Ed has been hired by a private company to connect two remote sites with a wide area network (WAN). Each of these sites has more than 200 users, and they all need to constantly transfer files across the WAN. One of the sites has a customer database that is accessed by both sites at all hours of the day. Access to the database and other information is time sensitive and constant. The company estimates that their aggregate bandwidth needs to be approximately 40 Mbps. Management says that they need to guarantee access to this information and that money is not a factor in the WAN implementation. Which WAN technology should Ed recommend for this scenario?
A. A standard modem-to-modem connection
B. A T-3 dedicated leased line
C. An ISDN (Integrated Services Digital Network) Primary Rate Interface (PRI) connection
D. An ADSL (Asymmetrical Digital Subscriber Line) connection
B. A T-3 dedicated leased line
For this scenario, the best solution is a dedicated leased line connection. This is because the bandwidth requirements are constant and the data transfer rates are high. To support the 40 Mbps data rate, Ed should recommend a T-3 dedicated leased line, running at 44.735 Mbps. Standard modem connections, ADSL, and an ISDN PRI connection are all too slow.
A load balancer is a type of which of the following devices?
A. Switch
B. Router
C. Gateway
D. Firewall
B. Router
A load balancer is a type of router that forwards traffic with a single IP address to multiple servers in turn. In most cases, a load balancing router works by processing incoming traffic based on rules set by the administrator. Because a load balancer works with IP addresses, it is a network layer device. Load balancers are not switches, gateways, or firewalls.
In its primary functionality, a network attached storage (NAS) device is most closely associated with which of the following devices?
A. Failover cluster
B. File server
C. JBOD
D. RAID
B. File server
A NAS device is essentially a file server that connects to a network and provides users with access to shared files. A NAS is a single computer, so it cannot be associated with failover clustering. Just a Bunch of Disks (JBOD) is a simple storage array that provides block-level access to data, whereas NAS devices provide file-level access. Redundant Array of Independent Disks (RAID) is a fault tolerance technology that might be implemented in NAS devices, but it is not the device’s primary function.
Which of the following signal types is carried by copper cable?
A. Fiber optic
B. Microwave
C. Infrared
D. Electrical
D. Electrical
Copper cables use electrical signals to transmit data. Fiber optic is a cable type, not a signal type. Microwave signals can’t be transmitted over copper cable. Infrared signals are used only for wireless networks.
Which of the following protocols uses jumbo frames to increase performance levels on storage area networks?
A. Ethernet
B. IP
C. Fibre Channel
D. iSCSI
A. Ethernet
Ethernet uses jumbo frames to transfer large amounts of data more efficiently. On a packet-switched network, each packet requires header data, which adds to the network’s transmission overhead. Splitting large files into a great many small packets can lead to so much overhead that network efficiency is impaired. Ethernet typically restricts frame size to 1,500 bytes, but jumbo frames enable Ethernet systems to create frames up to 9,000 bytes. Frames are data link layer protocol data units, so Internet Protocol (IP), operating at the network layer, is not involved in creating them. Fibre Channel and iSCSI are specialized storage area networking protocols that do not use jumbo frames.
The network administrator for a small business is installing a computer to function as a firewall protecting their internetwork from Internet intrusion. At which of the following locations should the administrator install the firewall system?
A. Anywhere on the private internetwork, as long as the Internet is accessible
B. Between the Internet access router and the Internet service provider’s (ISP’s) network
C. At the ISP’s network site
D. Between the Internet access router and the rest of the private internetwork
D. Between the Internet access router and the rest of the private internetwork
The firewall is a conduit between the private network and the ISP’s network (which provides access to the Internet), through which all traffic must pass. This ensures that the firewall has the opportunity to examine every packet that passes between the private network and the Internet and filter out those that are not authorized. If the firewall was located in the midst of the private internetwork, it would be possible for Internet computers to bypass the firewall and communicate directly with the private systems. Placing the firewall on the far side of the router would put it on the ISP’s network, causing it to filter all of the ISP’s traffic and not just that destined for the private network. Installing the firewall at the ISP’s site would have the same effect as installing it on the far side of the router at the private network site.
Which of the following telecommunications components is all but obsolete and is found only in old, analog telephone installations?
A. 66 block
B. 110 block
C. Patch panel
D. Smart jack
A. 66 block
A 66 block is a type of punchdown block for telephone systems that was first introduced in 1962. By the year 2000, nearly all commercial telephone installations had begun using 110 blocks instead; 110 blocks are still in use, as are patch panels and fiber distribution panels, both of which are termination points for network cable runs.
Which of the following devices is used to physically connect computers in the same VLAN?
A. A bridge
B. A hub
C. A switch
D. A router
C. A switch
Replacing routers with switches turns an internetwork into a single large subnet, and VLANs exist as logical elements on top of the switching fabric. Although VLANs are the functional equivalent of network layer subnets, the systems in a single VLAN are still connected by switches, not routers. Bridges connect network segments at the data link layer and selectively forward traffic between the segments. However, bridges do not provide a dedicated connection between two systems like a switch does, and they do not make it possible to convert a large routed internetwork into a single switched network. Therefore, they have no role in implementing VLANs. Hubs are physical layer devices that propagate all incoming traffic out through all of their ports. Replacing the routers on an internetwork with hubs would create a single shared network with huge amounts of traffic and collisions. Hubs, therefore, do not connect the computers in a VLAN.
Which of the following connector types was typically associated with a T-connector attached to the computer?
A. RJ45
B. MTRJ
C. 8P8C
D. BNC
E. F-type
D. BNC
Thin Ethernet networks use a type of coaxial cable that runs from each computer to the next one, forming a bus topology. To connect the cable to the network computers, each network interface adapter has a T-connector attached to it, with two additional male BNC connectors, to which you connect two lengths of network cabling.
Which of the following wide area network (WAN) services uses uniformly sized, 53-byte packets called cells?
A. ATM
B. Frame relay
C. T-1
D. PPPoE
A. ATM
Asynchronous Transfer Mode (ATM) transfers data using uniformly sized cells rather than same-sized packets. Frame relay uses variable-sized packets, and Point-to-Point Protocol over Ethernet (PPPoE) uses variable-sized Ethernet frames. A T-1 is a circuit-switched connection that does not use packets or cells.
Which of the following statements about Internet access through a proxy server accounts for the security against outside intrusion that a proxy provides?
A. The proxy server uses a public IP address and the client computers use private addresses.
B. The proxy server uses a private IP address and the client computers use public addresses.
C. Both the proxy server and the client computers use private IP addresses.
D. Both the proxy server and the client computers use public IP addresses.
A. The proxy server uses a public IP address and the client computers use private addresses.
Because the client computers use private IP addresses, they are invisible to the Internet, so users outside the private network cannot see or access them. The proxy server has a public IP address so it can participate in service transactions with Internet servers. If the proxy server used a private IP address, it would not be able to access the Internet directly. If the clients used public IP addresses, they would be visible to the Internet and vulnerable to intrusion.
Which of the following statements explains the purpose of the twists in twisted pair cabling?
A. The twists prevent collisions.
B. The twists completely eliminate crosstalk and electromagnetic interference (EMI) in adjacent wire pairs.
C. The twists prevent crosstalk in adjacent wire pairs and limit the effects of EMI on the signals carried over the cable.
D. The twists extend the bend radius allowance of the cable.
C. The twists prevent crosstalk in adjacent wire pairs and limit the effects of EMI on the signals carried over the cable.
The twists in a twisted pair cable prevent the signals on the different wires from interfering with each other (which is called crosstalk) and also provide resistance to outside electromagnetic interference. The twists have no effect on collisions. The twists can’t completely eliminate the effects of EMI. Twists have nothing to do with the bend radius allowance for the cable.
In which of the following ways does a virtual switch differ from a physical switch?
A. Virtual switches have an unlimited number of ports, whereas physical switches have a specific number.
B. Physical switches typically support the creation of VLANs, whereas virtual switches do not.
C. Virtual switches cannot forward traffic to the host server running them, whereas physical switches can forward traffic to all connected computers.
D. Physical switches always include layer 3 functionality, whereas virtual switches do not.
A. Virtual switches have an unlimited number of ports, whereas physical switches have a specific number.
It is true that virtual switches can have unlimited ports, whereas physical switches are limited to the number of physical ports in the device. Both virtual and physical switches can support virtual local area networks (VLANs). Virtual switches can forward traffic to the host server. Physical switches do not always include layer 3 (routing) functionality.
What is the highest possible data transfer rate on a storage area network (SAN) using Fibre Channel?
A. 8 Gbps
B. 16 Gbps
C. 32 Gbps
D. 128 Gbps
E. 256 Gbps
D. 128 Gbps
The current Fibre Channel standard calls for a maximum data transfer rate of 128 gigabits per second (Gbps), for a nominal throughput of 12,800 megabytes per second (MBps).
Which of the following protocols is not used for storage area networking (SANs)?
A. iSCSI
B. FCoE
C. VoIP
D. Fibre Channel
C. VoIP
Voice over Internet Protocol (VoIP) is a technology for the transmission of voice communications over IP networks; it is not a SAN protocol. Internet Small Computer Systems Interface (ISCSI), Fibre Channel over Ethernet (FCoE), and Fibre Channel are all SAN protocols.
Which of the following technologies is typically associated with virtual PBX services?
A. Quality of service
B. Voice over IP
C. CARP
D. Round-robin DNS
B. Voice over IP
A virtual PBX is an arrangement in which a telephone company provides the PBX services to a customer but maintains the actual hardware at their own facility. The recent emphasis on cloud computing has led to a number of hosted PBX solutions that use Voice over IP (VoIP) to provide services to customers. Quality of service (QoS) is a technique for prioritizing traffic by tagging packets based on their content. It is not a virtual PBX technique. The Cache Array Routing Protocol (CARP) enables proxy servers to exchange information; it does not provide virtual PBX services. In round-robin DNS, a DNS server contains multiple resource records for the same server name, each with a different IP address representing one of the computers running the server application. When a client resolves the server name, the DNS server accesses each of the resource records in turn so that each address theoretically receives the same number of visitors. This is not a virtual PBX technology.
Which of the following is a device that switches calls between endpoints on the local IP network and provides access to external Internet lines?
A. VoIP PBX
B. VoIP gateway
C. VoIP endpoint
D. Multilayer switch
A. VoIP PBX
A private branch exchange (PBX) switches internal calls and provides access to external lines. A VoIP PBX performs the same tasks as a traditional PBX. A VoIP gateway is the device that provides the conduit between an IP network and the Public Switched Telephone Network (PSTN). A VoIP endpoint is a device that makes use of the VoIP system, such as a computer or handset. A multilayer switch is a data networking device that includes both switching and routing capabilities.
Which of the following devices can administrators used to create multiple virtual local area networks (VLANs) and forward traffic between them?
A. Multilayer switch
B. Virtual router
C. Load balancer
D. Broadband router
A. Multilayer switch
A multilayer switch is a network connectivity device that function at both layer 2 and layer 3 of the OSI model. At layer 2, the device functions like a normal switch, providing individual collision domains to each connected node and enabling administrators to create multiple VLANs. At layer 3, the device also provides routing capabilities by forwarding packets between the VLANs. Virtual routers, load balancers, and broadband routers are strictly layer 3 devices that can route traffic but cannot create VLANs.
Which of the following terms is used to describe the method by which a firewall examines the port numbers in transport layer protocol headers?
A. IP address filtering
B. Service-dependent filtering
C. Deep packet inspection
D. Next generation firewall
B. Service-dependent filtering
Service-dependent filtering blocks traffic based on the port numbers specified in the transport layer header fields. Because port numbers represent specific applications, you can use them to prevent traffic generated by these applications from reaching a network. IP address filtering operates at the network layer. Deep packet inspection (DPI) scans the contents of packets, rather than their headers. Next generation firewall (NGFW) defines a device with advanced protection capabilities; port number scanning is a basic firewall function.
Which of the following protocol standards defines a layered implementation that does not correspond to the layers of the Open Systems Interconnection (OSI) model?
A. iSCSI
B. Fibre Channel
C. PPP
D. RDMA
B. Fibre Channel
The Fibre Channel standard defines a five-layer networking stack, with layers numbered FC-0 to FC-4, that does not correspond to the layers of the OSI model. Internet Small Computer System Interface (iSCSI), Point-to-Point Protocol (PPP), and Remote Direct Memory Access (RDMA) all function within the standard OSI model layers.
To which of the following Internet connection types does a specification called DOCSIS apply?
A. Dial-up modem
B. DSL
C. Cable broadband
D. ISDN
C. Cable broadband
The Data Over Cable Service Interface Specification (DOCSIS) is a telecommunications standard that defines the manner in which data is to be transmitted over a cable television system. DOCSIS does not apply to dial-up modem, Digital Subscriber Line (DSL), and Integrated Services Digital Network (ISDN) connections.
Which of the following devices can split a single network into two collision domains while maintaining a single broadcast domain?
A. Hub
B. Bridge
C. Switch
D. Router
B. Bridge
A bridge can split a single network into two collision domains, because it forwards only the packets that are destined for the other side of the bridge. The bridge forwards all broadcast packets, so it maintains a single broadcast domain. A hub maintains a single collision domain and a single broadcast domain. A switch creates a separate collision domain for each port, and a single broadcast domain for the entire network. A router creates two collision domains, but it does not forward broadcasts, so there are two broadcast domains as well.
Which of the following is not a mechanism for distributing incoming network traffic among multiple servers?
A. Load balancer
B. Round-robin DNS
C. NLB cluster
D. VPN concentrator
D. VPN concentrator
A virtual private network (VPN) concentrator is a type of router that enables multiple client systems to access a network from remote locations. It does not distribute traffic among servers. A load balancer is a type of router that forwards traffic with a single IP address to multiple servers in turn. Round-robin DNS is a technique in which a DNS server resolves a name into several IP addresses, each in turn. A Network Load Balancing (NLB) cluster is a group of servers, all running the same application, that distribute incoming traffic among themselves.
Which DSL (Digital Subscriber Line) technology can adjust its transmission speed based on line conditions?
A. HDSL
B. IDSL
C. RADSL
D. VDSL
C. RADSL
Rate-Adaptive Digital Subscriber Line (RADSL) technology can adjust its rate of transmission based on line conditions. High-bit-rate Digital Subscriber Line (HDSL), Very high-rate Digital Subscriber Line (VDSL), and Internet Digital Subscriber Line (IDSL) do not use rate adaptive transmission.
Which of the following remote access technologies converts digital signals generated by a computer to analog signals that can be carried over standard telephone wires?
A. Modem-to-modem
B. Integrated Services Digital Network (ISDN)
C. Digital Subscriber Line (DSL)
D. Cable broadband
A. Modem-to-modem
Modem-to-modem connections use the existing analog Public Switched Telephone Network (PSTN) network to carry data over standard telephone lines. All modem-to-modem connections are limited to analog signaling and therefore must perform modulation and demodulation. This means that the modems convert digital signals to analog signals before transmitting them over the PSTN network. Modems then convert the digital signals back to analog at the destination. ISDN, DSL, and cable broadband all use digital signaling from end to end.
A T-3 leased line connection runs at 44.736 megabits per second (Mbps). How many separate channels does a T-3 provide?
A. 24
B. 64
C. 128
D. 512
E. 672
E. 672
A T-3 leased line connection is the equivalent of 28 T-1 connections. Each T-1 consists of 24 channels, so a T-3 has a total of 672 channels (28 × 24).
Which of the following statements about content filtering is true?
A. Content filters examine the source IP addresses of packets to locate potential threats.
B. Content filters enable switches to direct packets out through the correct port.
C. Content filters examine the data carried within packets for potentially objectionable materials.
D. Content filters use frequently updated signatures to locate packets containing malware.
C. Content filters examine the data carried within packets for potentially objectionable materials.
Content filters are a firewall feature that examines the data inside packets, rather than their origin, to locate objectionable material such as pornography. They do not scan IP addresses, nor do they detect typical types of malware. Content filters are not implemented in switches
Which of the following is the term for the client that accesses an iSCSI device on a storage area network?
A. Initiator
B. Target
C. Controller
D. Adapter
A. Initiator
The client side of an iSCSI implementation is called an initiator. The storage device to which the initiator connects is called a target. Controller and adapter are not terms used for iSCSI clients or servers.
Ralph is an employee of a company that offers the option to telecommute from home. As a telecommuting employee, he needs to connect to the company network to access client information, transfer files, and send email through a virtual private network (VPN) connection. Ralph is investigating the different wide area network (WAN) services available for the remote connection before he implements one. His home is over 30 years old; the existing telephone wiring was not run through conduit, and the wiring seems to be deteriorating. Ralph has cable television (CATV) service, and his home is also approximately 20,000 feet from the nearest telephone central office. He wants to implement the fastest remote connection service possible, but cost is a factor in the decision. Which WAN technology should Ralph implement?
A. A dedicated leased line (fractional T-1)
B. A standard modem-to-modem connection
C. A DSL (Digital Subscriber Line) connection
D. A broadband CATV connection
D. A broadband CATV connection
In this scenario, the best solution is for Ralph to use his existing CATV service the remote connection. CATV offers faster data rates than standard modem-to-modem service and supports VPN connections. A dedicated fractional T-1 line is expensive and is not typically used for remote user connections. Since Ralph’s telephone lines are not run through conduit and the distance to the central office is more than 18,000 feet, he probably cannot use DSL technology, because it requires good-quality lines and close proximity to a central office.
Which of the following combinations of attributes describes the cable used for a Thin Ethernet network?
A. RJ45, 50-ohm, 0.270-inch, coaxial cable with BNC connectors
B. RG-59, 75-ohm, 0.242-inch, coaxial cable with F connectors
C. RG-58, 50-ohm, 0.195-inch, coaxial cable with BNC connectors
D. RG-8, 50-ohm, 0.405-inch, coaxial cable with N connectors
E. RJ-6, 75-ohm, 0.242-inch, coaxial cable with BNC connectors
C. RG-58, 50-ohm, 0.195-inch, coaxial cable with BNC connectors
Thin Ethernet networks use a type of 50-ohm coaxial cable called RG-58, which is 0.195 inches in diameter and uses BNC connectors. 75-ohm coaxial cable with F connectors is used for cable television networks, and RG-8 coaxial is the cable that Thick Ethernet networks use.
Which of the following devices enables two computers to communicate when they are using different protocols at each layer of the Open Systems Interconnection (OSI) reference model?
A. A router
B. A switch
C. A hub
D. A gateway
D. A gateway
A gateway enables two devices using different protocols to communicate by performing translation and conversion services for them. Routers, hubs, and switches all require the same protocol at some of the OSI model layers.
Which of the following is not one of the criteria typically used by load balancers to direct incoming traffic to one of a group of servers?
A. Which server has the lightest load
B. Which server has the fastest response time
C. Which server is next in an even rotation
D. Which server has the fastest processor
D. Which server has the fastest processor
In most cases, a load balancing router works by processing incoming traffic based on rules set by the administrator. The rules can distribute traffic among a group of servers using various criteria, such as each server’s current load or response time or which server is next in a given rotation. Load balancers typically do not use the hardware configuration of the servers to direct traffic, since this is a factor that does not change.
Which of the following protocols are included in an FCoE packet?
A. Ethernet
B. IP
C. TCP
D. UDP
E. None of the above
A. Ethernet
Which of the following best describes the function of a virtual switch?
A. A virtual switch is a software product that enables a computer with multiple network adapters to function as a switch.
B. A virtual switch is a feature in layer 3 switches that enables VLANs on the same switch to communicate with each other.
C. A virtual switch is a feature in layer 3 switches that enables VLANs on different switches to communicate with each other.
D. A virtual switch enables virtual machines running on the same hypervisor to communicate with each other internally.
D. A virtual switch enables virtual machines running on the same hypervisor to communicate with each other internally.
In most virtualization products, when you create multiple virtual machines on one host computer, they can communicate with each other internally using a built-in virtual switching capability. A computer with multiple network adapters can function as a router, but not as a switch. Layer 3 switches can provide virtual routers that connect VLANs together, but not virtual switches. The function that enables VLANs on different switches to communicate is called trunking, not virtual switching.
Which of the following statements about routers is not true?
A. Routers can connect two or more networks with dissimilar data link layer protocols and media.
B. Routers can connect two or more networks with the same data link layer protocols and media.
C. Routers store and maintain route information in a local text file.
D. Servers with multiple network interfaces can be configured to function as software routers.
E. Routers can learn and populate their routing tables through static and dynamic routing.
C. Routers store and maintain route information in a local text file.
Routers store and maintain route information in a routing table that is stored in memory, not in a local text file. All of the other statements about routers are true.
Which of the following components is responsible for providing a virtualized hardware environment and running virtual machines?
A. Hypervisor
B. Virtual server
C. Virtual switch
D. VPN concentrator
A. Hypervisor
The hypervisor is the hardware or software component responsible for managing virtual machines and providing the virtualized hardware environment on which they run. Virtual servers and virtual switches are components that are part of the virtual network infrastructure enabled by the hypervisor. A virtual private network (VPN) concentrator is a type of router that enables multiple remote clients to connect to a network; it has nothing to do with virtual networking.
Which of the following best describes the function of a firewall?
A. A device located between two networks that enables administrators to restrict incoming and outgoing traffic
B. A device that connects two networks together, forwarding traffic between them as needed
C. A device that enables Internet network clients with private IP addresses to access the Internet
D. A device that caches Internet data for subsequent use by internal network clients
A. A device located between two networks that enables administrators to restrict incoming and outgoing traffic
A firewall is a filter that can prevent dangerous traffic originating on one network from passing through to another network. A device that connects two networks together and forwards traffic between them is a router, not a firewall. A device that enables Internet network clients with private IP addresses to access the Internet is a description of a NAT router or a proxy server, not a firewall. A device that caches Internet data is a proxy server or caching engine, not a firewall.
Which of the following is the primary reason why replacing hubs with switches on an Ethernet local area network (LAN) improves its performance?
A. Switches forward packets faster than hubs.
B. Switches do not forward broadcast transmissions.
C. Switches reduce the number of collisions on the network.
D. Switches read the IP addresses of packets, not the hardware addresses.
C. Switches reduce the number of collisions on the network.
The main reason why switches improve the efficiency of an Ethernet LAN is that they create a separate collision domain for each switched port, eliminating most collisions. Collisions result in packets having to be retransmitted, so fewer collisions means fewer retransmissions, which improves performance. Switches do not forward packets faster than hubs. Switches do forward broadcast transmissions. Switches do read hardware addresses, not IP addresses.
Alice is the administrator of a corporate network. The company has one main site and two branch offices, and Alice is responsible for implementing WAN connections between them. The two branch offices need to upload financial information to the main office at the end of each day. This information transfer consists of database files totaling 20 to 30 GB per site. Other than the exchange of financial information, no other user traffic will be transferred between the sites, and, for security reasons, the management wants to automatically disconnect the link when it is not in use, without having to manually unplug the service cable. Cost is a factor in determining which wide area network (WAN) technology to use. Which of the following WAN technologies best suits the company’s needs?
A. A dedicated leased line (fractional T-1)
B. A Public Switched Telephone Network (PSTN) modem connection
C. A Digital Subscriber Line (DSL) connection
D. A broadband cable television (CATV) connection
E. An Integrated Services Digital Network (ISDN) Primary Rate Interface (PRI) connection
E. An Integrated Services Digital Network (ISDN) Primary Rate Interface (PRI) connection
For this scenario, the only solution that meets all the company’s needs is an ISDN PRI connection. All of the specified options, except for the PSTN modem connection, provide sufficient bandwidth for the application. However, only the ISDN and PSTN links can be disconnected when not in use. Therefore, ISDN is the only possibility.
Proxy servers operate at which layer of the OSI reference model?
A. Data link
B. Network
C. Transport
D. Application
D. Application
A proxy server is an application layer service because it receives Internet service requests from client computers, reads the application layer protocol data in each request, and then generates its own request for the same service and transmits it to the Internet server the client specifies. Only an application layer service can read and process the application layer data in network packets. A proxy server cannot be a data link layer device because it can provide Internet access to an entire internetwork, while the data link layer is concerned with communications on a single subnet. Proxy servers cannot be network layer devices because the network layer handles all internetwork packets indiscriminately and is unaware of what application generated the data carried inside the packets. The transport layer is not involved in processing application data, so proxy servers cannot be said to function at the transport layer.
Which of the following is a PPP authentication protocol that enables users to authenticate using smartcards and fingerprint scanners, as well as usernames and passwords?
A. PPTP
B. PAP
C. CHAP
D. EAP
D. EAP
Extensible Authentication Protocol (EAP) is a shell protocol used with Point-to-Point Protocol (PPP), which enables systems to support various types of authentication mechanisms. The primary advantage of EAP is that it enables a computer to use mechanisms other than passwords for authentication, including public key certificates, smartcards, and biometric devices, such as fingerprint scanners. Password Authentication Protocol (PAP) and Challenge Handshake Authentication Protocol (CHAP) support only password authentication. Point-to-Point Tunneling Protocol (PPTP) is a virtual private networking (VPN) protocol, not an authentication protocol.
Five computers are connected to the same switch, but only four are able to communicate with each other. Assuming that all of the hardware is functioning properly, which of the following could be a reason for the fifth computer’s communication problem?
A. The switch has the fifth computer connected to a VLAN different from that of the other four.
B. The network is experiencing a switching loop.
C. The fifth computer is experiencing an MTU black hole, whereas the other four computers are not.
D. There is a virtual router between the fifth computer and the other four.
A. The switch has the fifth computer connected to a VLAN different from that of the other four.
If the fifth computer is in a different VLAN from the other four, it would be unable to communicate with them. A switching loop would affect communication between all of the computers, not just the fifth one. An MTU black hole is a condition in which a system is unable to complete the Path MTU Discovery process, due to an intervening firewall. Because these five computers are all on the same LAN, they all have the same MTU, and Path MTU Discovery is not necessary. A virtual router would enable switched computers on different subnets to communicate with each other; it would not prevent them from communicating.
A company is moving their entire operation to a new building, and part of the plan is to increase the speed of their Internet access by installing a leased T-3 line to replace their existing broadband connection. The service provider they have selected sends a technician to install the leased line. Which of the following is the correct term for the location in the new building where the technician will terminate the T-3?
A. Patch panel
B. Switch
C. Firewall
D. Demarc
D. Demarc
The demarc, or demarcation point, is the place where a service enters the building, and where the service provider’s physical layer responsibility ends. The patch panel, the switch, and the firewall are all inside the network, and they are the responsibility of the subscriber.
Which of the following bridging types has never been used on Ethernet local area networks (LANs)?
A. Store and forward
B. Transparent
C. Source route
D. Multiport
C. Source route
Source route bridging was a technique used on Token Ring (and not Ethernet) networks, in which a Routing Information Field (RIF) in the packet header identified the network segments the packet should follow to reach its destination. Store and forward, transparent, and multiport bridges have all been used on Ethernet networks.
Which of the following devices often provides diagnostic testing capabilities at the demarcation point of a leased line wide area network (WAN) service?
A. SIP trunk
B. Media converter
C. Smart jack
D. AAA server
C. Smart jack
A smart jack is a device located at the demarcation point of a leased line that can provide additional functions, such as signal conversion, diagnostic testing, and other capabilities. A Session Initiation Protocol (SIP) trunk is a connection to a Voice over Internet Protocol (VoIP) service provider. A media converter is a local area networking devices that connects different cable types to the same network. An AAA server provides authentication, authorization, and accounting services for remote access servers.
In the punchdown process for unshielded twisted pair (UTP) cable, which of the following is the last step that you perform when connecting bulk cables to jacks in wall plates and patch panels?
A. Cut off the excess wire that protrudes past the contacts.
B. Press the bare wire down between the two metal contacts that hold it in place.
C. Strip some of the insulating sheath off the cable end to expose the wires.
D. Insert the wires into the appropriate contacts in the jack.
E. Strip a small amount of insulation off each wire.
F. Separate the twisted wire pairs at the ends.
A. Cut off the excess wire that protrudes past the contacts.
You use a punchdown block tool to connect the ends of bulk cable runs to jacks in wall plates and patch panels. The steps of the process are as follows:
Strip some of the insulating sheath off the cable end to expose the wires.
Separate the twisted wire pairs at the ends.
Strip a small amount of insulation off each wire.
Insert the wires into the appropriate contacts in the jack.
Press the bare wire down between the two metal contacts that hold it in place.
Cut off the excess wire that protrudes past the contacts.
You must repeat the process of punching down for both ends of your internal cable runs.
Review the following figure. Note that each store-and-forward switch has three connected node ports and one port for switch-to-switch connections. All node ports and links are configured for half-duplex communication. The switch-to-switch links are configured for full-duplex communication. Which of the following statements about the switched network is true?
A. There are 9 collision domains, one for each half-duplex connection.
B. There are 12 collision domains, one for each switch connection.
C. There are 3 collision domains, one for each switch-to-switch connection.
D. There is one collision domain for this network.
A. There are 9 collision domains, one for each half-duplex connection.
All half-duplex port connections on a store-and-forward switch represent a different collision domain. Full-duplex connections aren’t subject to collisions, so they do not define separate collision domains.
Review the following figure. How many collision domains and broadcast domains exist in the network diagram?
A. There are three collision domains and three broadcast domains.
B. There is one collision domain and three broadcast domains.
C. There is one broadcast domain and three collision domains.
D. There are no collision domains and only one broadcast domain.
E. There are nine collision domains and three broadcast domains.
A. There are three collision domains and three broadcast domains.
Each port on a router defines a separate collision domain. Hubs forward all traffic to all of the connected nodes, so each network segment is a single-collision domain. Routers do not forward broadcasts, so each network segment is also a separate broadcast domain.
