computer networks study set/ homework set

Limiting use of resources or capabilities to given users. -Encryption -Authentication -Access control -Firewall -Digital signature

-Access control

Provides confidentiality by encoding contents -Firewall -Encryption -Digital signature -Authentication -Access control

-Encryption

Which of the functions below belong in the controller layer labeled "Communication to/from controlled device"? Check all below that apply. *see image 5* -Statistics -Host information -OpenFlow protocol -Flow tables -Intent -Network graph -Link-state information -Switch information

-OpenFlow protocol

6.4-1. Different types of addressing (a). We've now learned about both IPv4 addresses and MAC addresses. Consider the address properties below, and use the pulldown menu to indicate which of these properties is only a property of MAC addresses (and therefore is not a property of IPv4 addresses - careful!). -This is a 32-bit address. -This is a 48-bit address. -This is a 128-bit address. -This is a link-layer address. -This is a network-layer address. -This address must be unique among all hosts in a subnet. -This address remains the same as a host moves from one network to another. -This address is allocated by DHCP.

-This is a 48-bit address. -This is a link-layer address. -This address remains the same as a host moves from one network to another.

Which of the functions below belong in the controller layer labeled "Network-wide distributed, robust state management"? Check all below that apply. *see image 5* -Statistics -Host information -OpenFlow protocol -Flow tables -Intent -Network graph -Link-state information -Switch information

-Statistic -Host information -Flow tables -Link-state information -Switch information

6.3-7. Characteristics of Multiple Access Protocols (d). Consider the following multiple access protocols that we've studied: (1) TDMA, and FDMA (2) CSMA (3) Aloha, and (4) polling. For which of these protocols ss there a maximum amount of time that a node knows that it will have to wait until it can successfully gain access to the channel? -TDMA and FDMA -Aloha -CSMA and CSMA/CD -Polling

-TDMA and FDMA -Polling

6.4-2. Different types of addressing (b). We've now learned about both IPv4 addresses and MAC addresses. Consider the address properties below, and use the pulldown menu to indicate which of these properties is only a property of IPv4 addresses (and therefore is not a property of MAC addresses - careful!). -This is a 32-bit address. -This is a 48-bit address. -This is a 128-bit address. -This is a link-layer address. -This is a network-layer address. -This address must be unique among all hosts in a subnet. -This address remains the same as a host moves from one network to another. -This address is allocated by DHCP.

-This is a 32-bit address. -This is a network-layer address. -This address is allocated by DHCP.

6.4-7. Learning switch scenario. Consider the simple star-connected Ethernet LAN shown below, and suppose the Ethernet switch is a learning switch, and that the switch table is initially empty. Suppose C sends an Ethernet frame address to C' and C ' replies back to C. How many of these two frames are also received at B's interface? *see image 6* 0 1 2 4

1

Suppose a provider network only wants to carry traffic to/from its customer networks (i.e., to provide no transit service), and customer networks only want to carry traffic to/from itself. Consider the figure below. To implement this policy, to which of the following networks would network C advertise the path Cy? *see image 2* B A x w

B A x

Consider the graph shown below and the use of Dijkstra's algorithm to compute a least cost path from a to all destinations. Suppose that nodes b and d have already been added to N'. What is the next node to be added to N' (refer to the text for an explanation of notation). *see image 1* c e f

e

Again, suppose a provider network only wants to carry traffic to/from its customer networks (i.e., to provide no transit service), and customer networks only want to carry traffic to/from itself. Suppose C has advertised path Cy to A. To implement this policy, to which of the following networks would network A advertise the path ACy? *see image 2* B A x w

w

Proving you are who you say you are -Access control -Authentication -Digital signatures -Firewall -Encryption

-Authentication

7.4-3. Reliable data transfer at the link layer. Which of the following statements is true about the link-level service of reliable data transfer (using ACKs) in WiFi (802.11) networks and in 4G cellular networks? -Both WiFi and LTE provide link-level reliable data transfer. -Neither WiFi nor LTE provide link-level reliable data transfer. -LTE provides link-level reliable data transfer but WiFi does not. -WiFi provides link-level reliable data transfer but LTE does not.

-Both WiFi and LTE provide link-level reliable data transfer.

Used to detect tampering/changing of message contents, and to identify the originator of a message. -Digital signature -Access control -Authentication -Firewall -Encryption

-Digital signature

Specialized "middleboxes" filtering or blocking traffic, inspecting packet contents inspections -Firewall -Encryption -Digital signatures -Access control -Authentication

-Firewall

6.4-5. Switch forwarding and filtering. Suppose an Ethernet frame arrives to an Ethernet switch, and the Ethernet switch does not know which of its switch ports leads to the node with the given destination MAC address? In this case, what does the switch do? -Choose a port randomly and forward the frame there. -Use the address resolution protocol (ARP) to determine the appropriate outgoing port. -Flood the frame on all ports except the port on which the frame arrived. -Drop the frame without forwarding it.

-Flood the frame on all ports except the port on which the frame arrived.

7.3.2. RTS/CTS frames. What is the purpose of RTS (request to send) and CTS (clear to send) frames in WiFi (802.11) networks? Select one or more of the answers below. [Hint: check two answers below]. -RTC/CTS frames allow a sender to gather CTS frames from all other network nodes, so that it knows it can then send without collisions. -A CTS allows a receiver to let the sender (who sent that RTS) know that it (the receiver) has enough buffers to hold a frame transmitted by that sender -A CTS that is sent allows a receiver to force other nodes (other than the intended sender who sent the RTS) to refrain from transmitting, thus allowing the sender who sent the RTS to then transmit a frame with less likelihood of a collision. -RTC/CTS frames helps nodes in a wireless network mitigate the effects of the hidden terminal problem.

-A CTS that is sent allows a receiver to force other nodes (other than the intended sender who sent the RTS) to refrain from transmitting, thus allowing the sender who sent the RTS to then transmit a frame with less likelihood of a collision. -RTC/CTS frames helps nodes in a wireless network mitigate the effects of the hidden terminal problem.

7.3-1. Beacon Frames. What is the purpose of a beacon frame in WiFi (802.11) networks? -A beacon frame allows a mobile device to signal that it is ready to receive a frame. -A beacon frame allows an access point to advertise its existence, and the frequency channel it is operating on, to devices that want to connect to an access point. -A beacon frame allows a node with a directional antenna to aim the antenna towards the beacon point to maximize the quality of the send and receive signal. -A beacon frame allows a mobile node to determine the direction in which it should move in order to obtain an increasing signal strength.

-A beacon frame allows an access point to advertise its existence, and the frequency channel it is operating on, to devices that want to connect to an access point.

6.4-6. Self-learning switches. Which of the following statements are true about a self learning switch? -A self-learning switch never forgets a self-learned association of a MAC address x and switch port y. -A self learning switch associates the source MAC address on an incoming frame with the port on which it arrived, and stores this matching in a table. The switch has now learned the port that leads to that MAC address. -A self-learning switch will age-out (forget) a self-learned association of a MAC address x and switch port y if it doesn't see a frame with MAC address x incoming on switch port y after some amount of time. -A self-learning switch frees a network manager from a least one configuration task that might be associated with managing a switch

-A self learning switch associates the source MAC address on an incoming frame with the port on which it arrived, and stores this matching in a table. The switch has now learned the port that leads to that MAC address. -A self-learning switch will age-out (forget) a self-learned association of a MAC address x and switch port y if it doesn't see a frame with MAC address x incoming on switch port y after some amount of time. -A self-learning switch frees a network manager from a least one configuration task that might be associated with managing a switch

6.4-8. Learning switch state removal. Consider the simple star-connected Ethernet LAN shown below, and suppose the switch table contains entries for each of the 6 hosts. How will those entries be removed from the switch table? *See image 6* -They'll remain in the switch forever (or until it is re-booted). -An entry for a host will be removed if that host doesn't transmit any frames for a certain amount of time (that is, table entries will timeout). -A table entry for a host will be removed by the STPP (Switch Table Purge Protocol) which will be used by a host to signal the switch when it (the host) is shutting down or otherwise leaving the network. -The table entry can only be removed by the network manager, who would use the SNMP protocol to remove the entry.

-An entry for a host will be removed if that host doesn't transmit any frames for a certain amount of time (that is, table entries will timeout).

7.4-2. IMSI. In 4G LTE cellular systems, what is an International Mobile SubscriberIdentity (IMSI)? -Assigned by a mobile carrier network to a device, when the device attaches to the radio access network, serving a similar link-layer role as MAC addresses in a wired network. -A fancy name for a globally unique phone number, including country code. -A 64-bit identifier that identifies the cellular network to which an mobile subscriber is attaching. Somewhat analogous to the Autonomous System (AS) number used in BGP to identify/name networks. -A 64-bit identifier stored on a cellular SIM (Subscriber Identity Module) card that identifies the subscriber in the worldwide cellular carrier network system.

-Assigned by a mobile carrier network to a device, when the device attaches to the radio access network, serving a similar link-layer role as MAC addresses in a wired network.

7.3-3. Why three addresses? Why does the WiFi (802.11) link-layer frame have three addresses? [Note: WiFi actually has four MAC addresses in the frame, but we're only focusing here on the three widely used ones]. -Because there may be two hosts or routers that are possible destinations for this link-layer frame and we need to identify which of these is the intended receiver. -Because both the access point that will relay this frame to the intended link-layer receiving host or router interface, as well as that intended destination host or router interface need to be specified. -Because the sender of this frame can be either the access point or a link-layer host or router interface, and we need to identify which of these two is the sender.

-Because both the access point that will relay this frame to the intended link-layer receiving host or router interface, as well as that intended destination host or router interface need to be specified.

7.3.2. Use of ACKs in WiFi. Why are link-layer ACKs used in WiFi (802.11) networks? [Hint: check two of the boxes below]. -Hearing a receiver ACK, all other stations will stop transmitting. This reduces collisions. -Because of the hidden terminal problem, a node that is transmitting and hears no collisions still doesn't know if there was a collision at the receiver. -Wireless links are noisier than wired links, and so bit level errors are more likely to occur, making link-layer error recovery more valuable that in less-noisy wired links. -The sender can used the differences in the signal strength in an ACK to infer whether the receiver is moving towards, or away from, the sender

-Because of the hidden terminal problem, a node that is transmitting and hears no collisions still doesn't know if there was a collision at the receiver. -Wireless links are noisier than wired links, and so bit level errors are more likely to occur, making link-layer error recovery more valuable that in less-noisy wired links.

Which of the functions below belong in the controller layer labeled "Interface, abstractions for network control apps"? Check all below that apply. *see image 5* -Statistics -Host information -OpenFlow protocol -Flow tables -Intent -Network graph -Link-state information -Switch information

-Intent -Network graph

Consider the SDN layering shown below. Match each layer name below with a layer label (a), (b) or (c) as shown in the diagram. *see image 4* -SDN Controller (network operating system) -SDN-controlled switches -Network-control applications

-SDN Controller (network operating system) (b) -SDN-controlled switches (c) -Network-control applications (a)

7.3-6. Bluetooth. Which of the following statement are true about the Bluetooth protocol? -Bluetooth transmission rates can be as high as in WiFi networks. -Bluetooth transmits all frames in the same frequency band. -Bluetooth networks have a centralized controller that serves to coordinate the various client devices in a Bluetooth piconet. -Bluetooth uses TDM, FDM, polling, error detection and correction, and has sleep modes to conserve device power. Pretty sophisticated for a consumer technology!

-Bluetooth uses TDM, FDM, polling, error detection and correction, and has sleep modes to conserve device power. Pretty sophisticated for a consumer technology!

Match the name of a general approach to routing with characteristics of that approach. -Centralized, global routing. -Decentralized routing. -Static routing. -Dynamic routing.

-Centralized, global routing: All routers have complete topology, and link cost information -Decentralized routing: An iterative process of computation, exchange of information with neighbors. Routers may initially only know to link costs to... (cut off) -Static Routing: Routes change slowly over time -Dynamic routing: routing changes quickly over time

6.4-4. Fields in an Ethernet frame. Use the pulldown menus below to match the name of the field with the function/purpose of a field within an Ethernet frame. -Cyclic redundancy check (CRC) field -Source address field -Data (payload) field -Type field. -Sequence number field

-Cyclic redundancy check (CRC) field: Used to detect and possibly correct bit-level errors in the frame. -Source address field: 48-bit MAC address of the sending node. -Data (payload) field: The contents of this field is typically (bit not always) a network-layer IP datagram. -Type field: Used to demultiplex the payload up to a higher level protocol at the receiver. -Sequence number field: This field does not exist in the Ethernet frame incorrect answers: -Used for flow control. -Used only to detect, but never correct, bit-level errors in the frame.

7.1-2. Infrastructure Mode. What is meant when we say that a network of devices is operating in "infrastructure mode"? -Devices communicate with each other and to the larger outside world via a base station (also known as an access point). -Network devices can communicate directly with each other, with no need for messages to be relayed through a base station. The devices are the "infrastructure". -All network equipment, except the mobile devices, must be racked in a temperature-controlled and power-smoothed building. -The mobile device is operating in a reduced power mode, forcing the network base station and routers to take on additional functionality that would normally be done by the mobile.

-Devices communicate with each other and to the larger outside world via a base station (also known as an access point).

-Which of the following statements correctly identify the differences between routing and forwarding? Select one or more statements. -Forwarding refers to moving packets from a router's input to appropriate router output, and is implemented in the data plane. -Forwarding refers to moving packets from a router's input to appropriate router output, and is implemented in the control plane. -Forwarding refers to determining the route taken by packets from source to destination, and is implemented in the control plane. -Forwarding refers to determining the route taken by packets from source to destination, and is implemented in the data plane. -Routing refers to moving packets from a router's input to appropriate router output, and is implemented in the data plane. -Routing refers to moving packets from a router's input to appropriate router output, and is implemented in the control plane. -Routing refers to determining the route taken by packets from source to destination, and is implemented in the data plane. -Routing refers to determining the route taken by packets from source to destination, and is implemented in the control plane.

-Forwarding refers to moving packets from a router's input to appropriate router output, and is implemented in the data plane. -Routing refers to determining the route taken by packets from source to destination, and is implemented in the control plane.

Consider routers 2c and 2d in Autonomous System AS2 in the figure below. Indicate the flavor of BGP and the router from which each of 2c and 2d learns about the path to destination x. *see image 3* -How does router 2c learn of the path AS3, X to destination network X? -How does router 2d learn of the path AS3, X to destination network X?

-How does router 2c learn of the path AS3, X to destination network X? From 3a via eBGP -How does router 2d learn of the path AS3, X to destination network X? From 2c via iBGP incorrect options: From 2c vis eBGP, From x vie eBGP, From 3a via iBGP

Consider Dijkstra's link-state routing algorithm that is computing a least-cost path from node a to other nodes b, c, d, e, f. Which of the following statements is true. -In the initialization step, the initial cost from a to each of these destinations is initialized to either the cost of a link directly connecting a to a direct neighbor, or infinity otherwise. -Following the initialization step, if nodes b and c are directly connected to a, then the least cost path to b and c will never change from this initial cost. -Suppose nodes b, c, and d are in the set N'. These nodes will remain in N' for the rest of the algorithm, since the least-cost paths from a to b, c, and d are known. -The values computed in the vector D(v), the currently known least cost of a path from a to any node v, will never increase following an iteration. -The values computed in the vector D(v), the currently known least cost of a path from a to any node v, will always decrease following an iteration.

-In the initialization step, the initial cost from a to each of these destinations is initialized to either the cost of a link directly connecting a to a direct neighbor, or infinity otherwise. -Suppose nodes b, c, and d are in the set N'. These nodes will remain in N' for the rest of the algorithm, since the least-cost paths from a to b, c, and d are known. -The values computed in the vector D(v), the currently known least cost of a path from a to any node v, will never increase following an iteration.

Match the terms "interdomain routing" and intradomain routing" with their definitions. Recall that in Internet parlance, an "AS" refers to "Autonomous System" - a network under the control of a single organization. -interdomain routing -intradomain routing

-Interdomain routing: Routing among different ASes ("networks") -Intradomain routing: routing among routers within the same ASes ("network")

Consider the OSPF routing protocol. Which of the following characteristics are associated with OSPF (as opposed to BGP)? -Is an intra-domain routing protocol. -Finds a least cost path from source to destination. -Floods link state control information. -Is an inter-domain routing protocol. -Policy, rather than performance (e.g., least cost path), determines paths that used.

-Is an intra-domain routing protocol. -Finds a least cost path from source to destination. -Floods link state control information.

Among the following protocols, terminology or considerations, indicate those that are associated with "routing within a single network (typically owned and operated by one organization)." -BGP -OSPF -inter-AS routing -intra-AS routing -inter-domain routing -intra-domain routing -Driven more by performance than by routing policy -Driven more by routing policy than end-end routing performance

-OSPF -intra-AS routing -intra-domain routing -Driven more by performance than by routing policy

Check the one or more of the following statements about the OSPF protocol that are true. -The Open Shortest Path First (OSPF) Internet routing protocol implements a Bellman-Ford distance-vector routing algorithm. -OSPF implements hierarchical routing -OSPF is an intra-domain routing protocol. -OSPF is an interdomain routing protocol. -OSFP uses a Dijkstra-like algorithm to implement least cost path routing.

-OSPF implements hierarchical routing -OSPF is an intra-domain routing protocol. -OSFP uses a Dijkstra-like algorithm to implement least cost path routing.

7.3.2. Characteristics of wireless links. Which of the following statements about the characteristics of wireless links are true? -Path loss refers to the decrease in the strength of a radio signal as it propagates through space. -Path loss refers to link-layer frames that are corrupted due to the higher bit error rates in wireless channels. -Path loss refers to the dropping of link-layer frames that are being relayed among wireless access points due to buffer overflow, just as network-layer datagrams are dropped at routers with full buffers. -The bit error rate (BER) of a wireless channel increases as the signal-to-noise ratio (SNR) increases. -The bit error rate (BER) of a wireless channel decreases as the signal-to-noise ratio (SNR) increases. -The "hidden terminal problem" refers to the fact that many people can never seem to find their mobile phones. -The "hidden terminal problem" happens when A sends to B over a wireless channel, and an observer, C (that can be even closer to A than B), does not detect/receive A's transmission because of physical obstacles in the path between A and C. -The "hidden terminal problem" happens when A sends to B over a wireless channel, and an observer, C (that can be even closer to A than B), does not detect/receive A's transmission because of physical obstacles in the path between A and B. -The "hidden terminal problem" happens when A sends to B over a wireless channel, and an observer, C (that is further away from A than B), does not detect/receive A's transmission because the signal strength of A's transmission has faded significantly by the time it reaches C. -Multipath propagation occurs when portions of the electromagnetic wave reflect off objects and the ground taking paths of different lengths between the sender and a receiver, and thus arriving at the receiver at slightly different points in time. -Multipath propagation occurs when a sender sends multiple copies of a frame to a receiver, which is relayed over different by base stations or other wireless devices to the receiver.

-Path loss refers to the decrease in the strength of a radio signal as it propagates through space. -The bit error rate (BER) of a wireless channel decreases as the signal-to-noise ratio (SNR) increases. -The "hidden terminal problem" happens when A sends to B over a wireless channel, and an observer, C (that can be even closer to A than B), does not detect/receive A's transmission because of physical obstacles in the path between A and C. -Multipath propagation occurs when portions of the electromagnetic wave reflect off objects and the ground taking paths of different lengths between the sender and a receiver, and thus arriving at the receiver at slightly different points in time.

Link-layer services. Which of the following services may be implemented in a link-layer protocol? Select one or more statements. -Reliable data transfer between directly connected nodes. -Lookup and forwarding on the basis of an IP destination address. -Flow control between directly connected nodes. -TLS security (including authentication) between directly connected nodes. -Coordinated access to a shared physical medium. -Bit-level error detection and correction. -Multiplexing down from / multiplexing up to a network-layer protocol. -End-end path determination through multiple IP routers.

-Reliable data transfer between directly connected nodes. -Flow control between directly connected nodes. -Coordinated access to a shared physical medium. -Bit-level error detection and correction. -Multiplexing down from / multiplexing up to a network-layer protocol.

What is the definition of a "good" path for a routing protocol? Chose the best single answer. -A high bandwidth path. -A low delay path. -A path that has little or no congestion. -A path that has a minimum number of hops. -Routing algorithms typically work with abstract link weights that could represent any of, or combinations of, all of the other answers.

-Routing algorithms typically work with abstract link weights that could represent any of, or combinations of, all of the other answers.

6.3-4. Characteristics of Multiple Access Protocols (a). Consider the following multiple access protocols that we've studied: (1) TDMA, and FDMA (2) CSMA (3) Aloha, and (4) polling. Which of these protocols are collision-free (e.g., collisions will never happen)? -TDMA and FDMA -Aloha -CSMA and CSMA/CD -Polling

-TDMA and FDMA -Polling

6.3-5. Characteristics of Multiple Access Protocols (b). Consider the following multiple access protocols that we've studied: (1) TDMA, and FDMA (2) CSMA (3) Aloha, and (4) polling. Which of these protocols requires some form of centralized control to mediate channel access? -TDMA and FDMA -Aloha -CSMA and CSMA/CD -Polling

-TDMA and FDMA -Polling

6.3-6. Characteristics of Multiple Access Protocols (c). Consider the following multiple access protocols that we've studied: (1) TDMA, and FDMA (2) CSMA (3) Aloha, and (4) polling. For which of these protocols is the maximum channel utilization 1 (or very close to 1)? -TDMA and FDMA -Aloha -CSMA and CSMA/CD -Polling

-TDMA and FDMA -Polling

7.3-5. The 802.11 Media Access Control protocol. Which of the following statement are true about the 802.11 (WiFi) MAC protocol? -The 802.11 MAC protocol performs carrier sensing. That is, it listens before transmitting and will only transmit if the channel is sensed idle. -The 802.11 MAC protocol performs collision detection. That is, an 802.11 sender will listen to the channel while it is transmitting, and stop transmitting when it detects a colliding transmission from another node. -The 802.11 MAC protocol performs collision avoidance. That is, an 802.11 sender and receiver can use approaches such as RTS/CTS, inter-frame spacing, and explicit acknowledgments to try avoid, rather than detect, colliding transmissions from another node.

-The 802.11 MAC protocol performs collision avoidance. That is, an 802.11 sender and receiver can use approaches such as RTS/CTS, inter-frame spacing, and explicit acknowledgments to try avoid, rather than detect, colliding transmissions from another node.

6.3-2. Pure Aloha and CSMA. Which of the following statements is true about both Pure Aloha, and CSMA (both with and without collision detection? -There can be simultaneous transmissions resulting in collisions. -There can be times when the channel is idle, when a node has a frame to send, but is prevented from doing so by the medium access protocol. -Pure Aloha and CSMA can achieve 100% channel utilization, in the case that all nodes always have frames to send. -Pure Aloha and CSMA can achieve 100% utilization, in the case that there is only one node that always has frames to send

-There can be simultaneous transmissions resulting in collisions. -Pure Aloha and CSMA can achieve 100% utilization, in the case that there is only one node that always has frames to send

Which of the following statements is true about channel partitioning protocols? -There can be simultaneous transmissions resulting in collisions. -There can be times when the channel is idle, when a node has a frame to send, but is prevented from doing so by the medium access protocol. -Channel partitioning protocols can achieve 100% channel utilization, in the case that all nodes always have frames to send. -Channel partitioning protocol can achieve 100% utilization, in the case that there is only one node that always has frames to send

-There can be times when the channel is idle, when a node has a frame to send, but is prevented from doing so by the medium access protocol. -Channel partitioning protocols can achieve 100% channel utilization, in the case that all nodes always have frames to send.

6.3-3. Polling and token-passing protocols. Which of the following statements is true about polling and token-passing protocols? -There can be simultaneous transmissions resulting in collisions. -There can be times when the channel is idle for more than a short period of time, when a node has a frame to send, but is prevented from doing so by the medium access protocol. -These protocol can achieve close to 100% channel utilization, in the case that all nodes always have frames to send (the fact that the utilization is close to, but not exactly, 100% is due to a small amount of medium access overhead but not due to collisions) -These protocol can achieve close 100% utilization, in the case that there is only one node that always has frames to send (the fact that the utilization is close to, but not exactly, 100% is due to a small amount of medium access overhead but not due to collisions)

-These protocol can achieve close to 100% channel utilization, in the case that all nodes always have frames to send (the fact that the utilization is close to, but not exactly, 100% is due to a small amount of medium access overhead but not due to collisions) -These protocol can achieve close 100% utilization, in the case that there is only one node that always has frames to send (the fact that the utilization is close to, but not exactly, 100% is due to a small amount of medium access overhead but not due to collisions)

6.4-3. Different types of addressing (c). We've now learned about both IPv4 addresses and MAC addresses. Consider the address properties below, and use the pulldown menu to indicate which of these properties is a property of both IPv4 addresses and MAC addresses. -This is a 32-bit address. -This is a 48-bit address. -This is a 128-bit address. -This is a link-layer address. -This is a network-layer address. -This address must be unique among all hosts in a subnet. -This address remains the same as a host moves from one network to another. -This address is allocated by DHCP.

-This address must be unique among all hosts in a subnet.

7-1-1. How fast is that wireless technology? Use the pulldown menus below to match the approximate transmission rate with the the wireless technology that achieves that rate. Of course, sender/receiver distance, noise and other factors determine actual transmission speed, so "your mileage may vary" (YMMV). -802.11 ax -5G celluar -802.11 ac -4G LTE -802.11 g -Bluetooth

-802.11 ax: 14 Gbps -5G cellular: 10 Gbps -802.11 ac: 3.5 Gbps -4G LTE: hundreds of Mbps -802.11 g: 54 Mbps -Bluetooth: 2 Mbps Other Incorrect Match Options: -PDN-Gateway (P-GW) -Mobile device

Consider the graph shown below and the use of Dijkstra's algorithm to compute a least cost path from a to all destinations. Suppose that nodes b and d have already been added to N'. What is the path cost to the next node to be added to N' (refer to the text for an explanation of notation). *see image 1* 4 5 6 7

4

Again, suppose a provider network only wants to carry traffic to/from its customer networks (i.e., to provide no transit service), and customer networks only want to carry traffic to/from itself. Suppose C has advertised path Cy to x. To implement this policy, to which of the following networks would network x advertise the path xCy? *see image 2* B A x w none of these other networks

none of these other networks