Networking Review

1. Which of the following cable types can be used to transmit one Gigabit Ethernet?
   
   A. Category 5
   B. Category 5e
   C. Category 6 and 6a
   D. Answers b and c
   E. None of the above
   Category 5e cable is an enhanced version of Category 5 which adheres to more stringent standards and is capable of transmitting data at speeds of up to 1 Gbps. Category 6 (6a) cable was designed to perform at frequencies of up to 250 MHz (500 MHz) and offers higher performance for better transmission of data at speeds up to 1 Gbps (10 Gbps).



2. Which wiring diagram demonstrates a correctly wired RJ45 connector?
   
   A.
   B.
   C.
   D. Answers a and b
   E. None of the above
   Diagrams a and b are EIA/TIA 568A and 568B and are the common wiring diagrams for RJ45 connectors. For patch cables, 568B wiring is by far, the most common wiring method. For a crossover cable, wire one end 568A and the other end 568B.



3. Which of the following are functions of Quality of Service (QoS)?
   
   A. Bandwidth Reservation - The ability to reserve a portion of bandwidth in a network or interface for a period of time, so that two devices can count on having that bandwidth for a particular operation
   B. Latency Management - A feature that limits the latency of data sent between two devices
   C. Traffic Prioritization - The ability to handle packets so that more important connections receive priority over less important ones
   D. All of the above
   E. None of the above
   The generic term 'Quality of Service' describes the characteristics of how data is transmitted between devices, rather than just how quickly it is sent. QoS features seek to provide more predictable streams of data rather than simply faster ones. Examples of such features include bandwidth reservation, latency minimums, traffic prioritization and shaping, and congestion limitation. Quality of service is more important for specialty applications such as multimedia than for routine applications such as those that transfer files or messages.



4. How many layers of network functions are in an OSI Reference Model?
   
   A. 4
   B. 7
   C. 11
   D. None of the above
   
   The most fundamental concept in the OSI Reference Model is the division of networking functions into a set of layers; from layer one at the bottom to layer seven at the top. As you go up the layer stack, you move away from concrete, hardware-specific functions to ones that are increasingly abstract, until reaching the realm of user applications at layer seven.



5. What IP addresses are considered private address blocks and can be used on any private network?
   
   A. 10.x.x.x
   B. 172.16.x.x through 172.31.x.x
   C. 192.168.0.x through 192.168.255.x
   D. All of the above
   E. None of the above
   10.x.x.x is the Class A private address block. 172.16.x.x through 172.31.x.x is the Class B private address block. 192.168.0.x through 192.168.255.x is the Class C private address block.



6. The ping utility is most useful for diagnosing the following types of problems?
   
   A. Whether or not the two devices on a network can communicate
   B. Whether network congestion or other problems exist that might allow communication to succeed sometimes, but cause it to fail in others
   C. Is a sonar pulse sent by a submarine to check for nearby objects
   D. Answers a and b
   E. None of the above
   The TCP/IP ping utility is used to verify the ability of two devices on a TCP/IP internetwork to communicate. It operates by having one device send ICMP Echo (Request) messages to another, which responds with Echo Reply messages. The program can be helpful in diagnosing a number of connectivity issues, especially if it is used to test the ability to communicate with other devices in different locations. It also allows the average round-trip delay to exchange messages with another device to be estimated.



7. What is DHCP?
   
   A. Each client leases an IP address from a DHCP server for a period of time
   B. Dynamic Assignment of IP Addresses
   C. Allows a pool if addresses to be shared amongst many machines
   D. All of the above
   E. None of the above
   DHCP defines three basic mechanisms for address assignment. Dynamic allocation is the method most often used, and works by having each client lease an address from a DHCP server for a period of time; the server chooses the address dynamically from a shared address pool.



8. What determines the speed of an Ethernet link?
   
   A. The capabilities of the network
   B. The capabilities of the device connected to the network
   C. The type of cable used to connect to the network
   D. All of the above
   E. None of the above
   All of the above