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| 1 | |
Packetizing at the network layer involves ___________________________. |
| | A) | encapsulating the payload at the source |
| | B) | adds a header that contains the source and destination information |
| | C) | decapsulating the payload at the destination |
| | D) | All of the choices are correct |
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| 2 | |
Routers in the path are not allowed to ___________________________. |
| | A) | fragment the packet they receive |
| | B) | decapsulate the packet |
| | C) | change source or destination address |
| | D) | All of the choices are correct |
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| 3 | |
The network layer in the Internet provides _________________. |
| | A) | comprehensive error and flow control |
| | B) | limited error control, but no flow control |
| | C) | comprehensive error control but limited flow control |
| | D) | All of the choices are correct |
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| 4 | |
In a virtual-circuit approach, the forwarding decision is based on the value of the _____________ field in the packet header. |
| | A) | source address |
| | B) | destination address |
| | C) | label |
| | D) | None of the choices are correct |
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| 5 | |
In a datagram approach, the forwarding decision is based on the value of the _____________ field in the packet header. |
| | A) | source address |
| | B) | destination address |
| | C) | label |
| | D) | None of the choices are correct |
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| 6 | |
The performance of a network can be measured in terms of ________. |
| | A) | delay |
| | B) | throughput |
| | C) | packet loss |
| | D) | All of the choices are correct |
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| 7 | |
Transmission delay (time) is the ratio of______________________. |
| | A) | transmission rate to packet length |
| | B) | transmission rate to distance |
| | C) | packet length to transmission rate |
| | D) | processing time to transmission rate |
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| 8 | |
Propagation delay (time) is the ratio of______________________. |
| | A) | transmission rate to propagation speed |
| | B) | propagation speed to distance |
| | C) | packet length to propagation speed |
| | D) | distance to propagation speed |
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| 9 | |
When the load in the network reaches the network capacity, the packet delay ___________ and the network throughput reaches ______________. |
| | A) | increases sharply; its minimum |
| | B) | increases sharply; its maximum |
| | C) | decreases sharply; its minimum |
| | D) | decreases sharply; its maximum |
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| 10 | |
In open-loop congestion control, policies are applied ____________________. |
| | A) | to prevent congestion before it happens |
| | B) | to alleviate congestion after it happens |
| | C) | to either prevent congestion before it happens or alleviate congestion after it happens |
| | D) | None of the choices are correct |
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| 11 | |
The __________________ technique is one of the open-loop congestion policies. |
| | A) | backpressure |
| | B) | choke packet |
| | C) | implicit signaling |
| | D) | None of the choices are correct |
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| 12 | |
The__________________ technique is one of the close-loop congestion policies. |
| | A) | acknowledgment policy |
| | B) | choke packet |
| | C) | discarding policy |
| | D) | None of the choices are correct |
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| 13 | |
An IPv4 address is normally represented in base ____ in dotted-decimal notation. |
| | A) | 16 |
| | B) | 256 |
| | C) | 10 |
| | D) | None of the choices are correct |
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| 14 | |
In classful addressing, the IPv4 address space is divided into _______ classes. |
| | A) | 3 |
| | B) | 4 |
| | C) | 5 |
| | D) | None of the choices are correct |
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| 15 | |
The number of addresses assigned to an organization in classless addressing _______. |
| | A) | can be any number |
| | B) | must be a multiple of 256 |
| | C) | must be a power of 2 |
| | D) | None of the choices are correct |
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| 16 | |
The first address assigned to an organization in classless addressing _______. |
| | A) | must be evenly divisible by the number of addresses in the organization |
| | B) | must be divisible by 128 |
| | C) | must belong to one of the A, B, or C classes |
| | D) | None of the choices are correct |
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| 17 | |
In subnetting, the number of addresses in each subnet must _______. |
| | A) | be a power of 2 |
| | B) | be a multiple of 128 |
| | C) | be divisible by 128 |
| | D) | None of the choices are correct |
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| 18 | |
What is the default prefix length for class A in CIDR notation? |
| | A) | 9 |
| | B) | 8 |
| | C) | 16 |
| | D) | None of the choices are correct |
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| 19 | |
What is the default prefix length for class B in CIDR notation? |
| | A) | 9 |
| | B) | 8 |
| | C) | 16 |
| | D) | None of the choices are correct |
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| 20 | |
What is the default prefix length for class C in CIDR notation? |
| | A) | 24 |
| | B) | 8 |
| | C) | 16 |
| | D) | None of the choices are correct |
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| 21 | |
DHCP is a (an) ___________ layer protocol. |
| | A) | application |
| | B) | transport |
| | C) | network |
| | D) | data-link |
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| 22 | |
In DHCP, the client uses ________ port and the server uses _________port. |
| | A) | an ephemeral; a well-known |
| | B) | a well-known; a well-known |
| | C) | a well-known; an ephemeral |
| | D) | None of the choices are correct |
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| 23 | |
DHCP uses the services of _______. |
| | A) | UDP |
| | B) | TCP |
| | C) | IP |
| | D) | None of the choices are correct |
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| 24 | |
_________ allows a site to use a set of private addresses for internal communication and a set of global Internet addresses for communication with the rest of the world. |
| | A) | DHCP |
| | B) | NAT |
| | C) | IMCP |
| | D) | None of the choices are correct |
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| 25 | |
The idea of address aggregation was designed to alleviate the increase in routing table entries when using ________ addressing. |
| | A) | classful |
| | B) | classless |
| | C) | classful or classless |
| | D) | None of the choices are correct |
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| 26 | |
The use of hierarchy in routing tables can ________ the size of the routing tables. |
| | A) | reduce |
| | B) | increase |
| | C) | neither reduce nor increase |
| | D) | None of the choices are correct |
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