您的位置：思科认证考试（ＣＣＮＡ）考试模拟题２０—３９及答案
20. [TxNx] If Host A sends a packet to Host B over token ring, and Host B is not
active:
a) The packet will time out.
b) The packet will be removed by Host A.
c) The NVRAM of Host B will remove the packet.
d) The packet will "die" when it reaches the terminator.
e) The packet will be removed by the token monitor.
21. [TxNx] If Host A sends a packet to Host B over token ring: Host A dies after
transmitting, and Host B is not active:
a) The packet will time out.
b) The packet will be removed by Host A.
c) The NVRAM of Host B will remove the packet.
d) The packet will "die" when it reaches the terminator.
e) The packet will be removed by the Active monitor.
22. [FxNx] BECN and FECN are:
a) Used to provide keepalives in a Frame Relay environment
b) Used to provide error checking in a Frame Relay environment
c) Used to provide congestion information in a Frame Relay environment
d) Used to provide flow control parameters in a Frame Relay environment
e) BECN and FECN are not used in a Frame Relay environment.
23. [RxNx] Which of the following are benefits of a Link-State routing protocol?
(Choose all that apply.)
a) Allows the use of a more robust addressing scheme.
b) Allows for a larger scalable network
c) Reduces convergence time
d) Allows "supernetting"
e) All of the above.
24. [OxNx] Which of the following are reasons for the OSI model?
a) Standardizes interfaces
b) Allows modular engineering
c) Facilitates learning and teaching
d) All of the above.
25. [RxNx] Which of the following is NOT a ROUTING protocol:
a) OSPF
b) RIP
c) IPX
d) EIGRP
e) NLSP
26. [RxNx] Which statement is NOT true about link state protocols:
a) Link state advertisements are sent to all routers in an area.
b) Each router executes the SPF algorithm.
c) Link state routers keep a topological database of the network.
d) Link state routers include the originating router s routing table.
e) Link state routers know of possible alternate paths to a particular network.
27. [RxNx] Which of the following would NOT appear in a routing table?
a) Next hop address
b) Interface Port references
c) MAC address
d) Network address
e) Metrics
28. [OxNx] Which statement is true of the Datalink OSI layer ?
a) 802.3 is the MAC sub layer.
b) No such thing
c) MAC sublayer provides the connection to the network layer.
d) MAC sublayer uses SAPS to access the network layer.
e) SAP sublayer uses the MAC layer to access the LAN medium.
29. [RINx] Given the IP address of 193.243.12.43 and a subnet mask of 255.255.255.128, what is the subnet address?
a) 194.243.12.32
b) 193.243.0.0
c) 194.243.12.43
d) 193.243.12.128
e) None of the above.
30. [CxNx] Cisco uses a naming convention to identify frame types. Which four
of the following mappings are correct?
Cisco_name = Common_name
a) cisco_II = Ethernet_II
b) arpa = Ethernet_II
c) sap = Ethernet_802.3
d) sap = Ethernet_802.2 LLC
e) Novell Ether = Ethernet_802.2 LLC
f) cisco_802 = Ethernet_802.2 LLC
g) snap = Token Ring Snap
h) snap = Ethernet_SNAP
31. [RxNx] In order to communicate throughout an internetwork, which of the
following are required. Choose Two.
a) The use of a routable protocol such as NetBEUI or LAT
b) A hierarchical naming scheme server such as DNS
c) A host file at each communicating device
d) A two part network addressing scheme such as Network/Host
e) The use of a routable protocol such as IP or IPX
f) The use of a routable protocol such as TCP or IPX
32. [CxNx] What is the default route on an IP network? Choose one.
a) This is the route that will be chosen first by IP for delivery of a datagram.
b) The address of the nearest downstream neighbor in a Token ring network.
c) At the router, it is the route used to direct frames for which the next hop has not been explicitly listed in the routing table.
d) Any static route listing in a routing table.
e) When all conditions are equal, the best route for delivery of IP datagrams.
33. [CxNx] A caret symbol (^) inserted into a failed command indicates which of
the following. Choose one.
a) Numeric data is required for this command.
b) The point in a command where you can simply press return to complete the syntax
string.
c) The point in a command where you have entered an incorrect command, keyword or
argument.
d) The point in a command where you must enter a required value.
e) This is a normal indicator for any failed command.
34. [RXNx] The metric used by IPX RIP is:
a) hops
b) ticks
c) cost
d) ticks and hops
e) None of the above.
35. [xINx] Which one of the following masks has the nickname of the "serial mask"?
a) 255.255.255.192
b) 255.255.255.224
c) 255.255.255.240
d) 255.255.255.248
e) 255.255.255.252
36. [SxNx] The following statement would deny traffic from what subnets?
Router_B(config)#access-list 101 deny
tcp 10.1.8.0 0.0.7.255
192.16.5.0 0.0.0.255
a) 10.1.8.0
b) 10.1.15.0
c) 10.1.0.0
d) 10.1.16.0
e) choice a and b
37. [SxNx] Name three reasons why VLAN s should be created.
a) Moves, Adds and Changes are made simpler.
b) There is less administrative overhead.
c) The switch can route between VLANS.
d) It limits broadcasts domains.
e) The router can switch faster.
38. [SxNx] The Catalyst 5000 uses which switching mode?
a) Cut-through
b) Store and forward
c) Fast switching
d) Choice a and b
e) Choice a and c
39. [OxNx] Which of the following layers defines data representation?
a) Application Layer 7
b) Presentation Layer 6
c) Session Layer 5
d) Transport Layer 4
e) Network Layer 3
f) Data Link Layer 2
g) Physical Layer 1
CCNA试题20-39答案
20. [TxNx] If Host A sends a packet to Host B over token ring, and Host B is not
active:
a) The packet will time out.
b) The packet will be removed by Host A.
c) The NVRAM of Host B will remove the packet.
d) The packet will "die" when it reaches the terminator.
e) The packet will be removed by the token monitor.
Answer
b) The packet will be removed by Host A.
21. [TxNx] If Host A sends a packet to Host B over token ring: Host A dies after
transmitting, and Host B is not active:
a) The packet will time out.
b) The packet will be removed by Host A.
c) The NVRAM of Host B will remove the packet.
d) The packet will "die" when it reaches the terminator.
e) The packet will be removed by the Active monitor.
Answer
e) The packet will be removed by the Active monitor.
22. [FxNx] BECN and FECN are:
a) Used to provide keepalives in a Frame Relay environment
b) Used to provide error checking in a Frame Relay environment
c) Used to provide congestion information in a Frame Relay environment
d) Used to provide flow control parameters in a Frame Relay environment
e) BECN and FECN are not used in a Frame Relay environment.
Answer
c) Used to provide congestion information in a Frame Relay environment
The following are definitions of each:
Backward Explicit Congestion Notification (BECN) - Bit set by a frame relay
network in frames traveling in opposite direction of frames encountering a
congested path. DTE receiving frames with the BECN bit set can request higher
level protocols take flow control action.
Forward Explicit Congestion Notification (FECN) - Bit set by a frame relay network
to inform DTE receiving frame that congestion was experienced in the path from
source to destination.
23. [RxNx] Which of the following are benefits of a Link-State routing protocol?
(Choose all that apply.)
a) Allows the use of a more robust addressing scheme.
b) Allows for a larger scalable network
c) Reduces convergence time
d) Allows "supernetting"
e) All of the above.
Answer
e) All of the above
24. [OxNx] Which of the following are reasons for the OSI model?
a) Standardizes interfaces
b) Allows modular engineering
c) Facilitates learning and teaching
d) All of the above.
Answer
d) All of the above
25. [RxNx] Which of the following is NOT a ROUTING protocol:
a) OSPF
b) RIP
c) IPX
d) EIGRP
e) NLSP.
Answer
c) IPX
There are routing protocols and routed protocols. Some examples of routed
protocols include IP, IPX, Appletalk and Decnet. A routed protocol travels through
the network. Routing protocols such as OSPF, IP RIP, IPX RIP, IGRP and EIGRP
represent the language that routers use to determine the best path through the
network.
26. [RxNx] Which statement is NOT true about link state protocols:
a) Link state advertisements are sent to all routers in an area.
b) Each router executes the SPF algorithm.
c) Link state routers keep a topological database of the network.
d) Link state routers include the originating router s routing table.
e) Link state routers know of possible alternate paths to a particular network.
Answer
d) Link state routers include the originating router s routing table.
Choice d is not true because during the flooding stage neighbor routers
communicate their directly connected networks. They DO NOT communicate
routing tables, as a Distance Vector routing protocol would.
27. [RxNx] Which of the following would NOT appear in a routing table?
a) Next hop address
b) Interface Port references
c) MAC address
d) Network address
e) Metrics
Answer
c) MAC address
A router is a device that operates at layer 3 where logical addresses are used,
not physical addresses. A switch or a bridge would contain MAC addresses in the
bridge table.
28. [OxNx] Which statement is true of the Datalink OSI layer ?
a) 802.3 is the MAC sub layer.
b) No such thing
c) MAC sublayer provides the connection to the network layer.
d) MAC sublayer uses SAPS to access the network layer.
e) SAP sublayer uses the MAC layer to access the LAN medium.
Answer
a) 802.3 is the MAC sub layer.
The IEEE subdivided the data link layer into two sublayers. 1) MAC Media Access
Control, which provides access to the LAN media 2) LLC Logical Link Control, which
provides protocols media independent access.
29. [RINx] Given the IP address of 193.243.12.43 and a subnet mask of
255.255.255.128, what is the subnet address?
a) 194.243.12.32
b) 193.243.0.0
c) 194.243.12.43
d) 193.243.12.128
e) None of the above.
Answer
e) none of the above
The address of 193.243.12.43/25 would be on the zero subnet and would be
represented as 193.243.12.0
I have used the slash format to represent the mask. This means that the first
25 bits represent the address of the wire.
30. [CxNx] Cisco uses a naming convention to identify frame types. Which four of
the following mappings are correct?
Cisco_name = Common_name
a) cisco_II = Ethernet_II
b) arpa = Ethernet_II
c) sap = Ethernet_802.3
d) sap = Ethernet_802.2 LLC
e) Novell Ether = Ethernet_802.2 LLC
f) cisco_802 = Ethernet_802.2 LLC
g) snap = Token Ring Snap
h) snap = Ethernet_SNAP
Answer
b) arpa = Ethernet_II
d) sap = Ethernet_802.2 LLC
g) snap = Token Ring Snap
h) snap = Ethernet_SNAP
Frame type naming has been an area of confusion since Novell chose to use a frame
type of 802.3 which differs from the IEEE 802.3 frame type format. This was
compounded when Novell changed their default frame type from 802.3 to 802.2.
Cisco has further confused this area by choosing another proprietary naming
scheme. Here is a chart that matches some common frame type names to the frame
type names used by Cisco and Novell.
Common Name Novel Name Cisco Name
Ethernet 2 Ethernet_II arpa
IEEE 802.3 Ethernet_802.2 sap
IEEE 802.3 with SNAP Ethernet_SNAP snap
Ethernet Ethernet_802.3 Novell ether
IEEE 802.5 with SNAP Token_ring snap
Note that Cisco can use the name snap to define two different frame types because
these names are assigned to either a Token Rring or an Ethernet interface. In
doing this the frame type name means something different to the router depending
upon the interface type it is assigned to.
31. [RxNx] In order to communicate throughout an internetwork, which of the
following are required. Choose Two.
a) The use of a routable protocol such as NetBEUI or LAT
b) A hierarchical naming scheme server such as DNS
c) A host file at each communicating device
d) A two part network addressing scheme such as Network/Host
e) The use of a routable protocol such as IP or IPX
f) The use of a routable protocol such as TCP or IPX
Answer
d) A two part network addressing scheme such as Network/Host
e) The use of a routable protocol such as IP or IPX
Explanation: Since an internetwork is made up of multiple logical networks with
hosts on each of those networks, a two-part addressing scheme is required so that
each can be identified. For example, IP uses a 32-bit number, which is really at least two separate numbers, one part for the network and one part for the host on
that network. In an IP number such as 131.108.25.165, the major network portion is
131.108, and, assuming we are not subnetting, the host portion is 25.165. Both IP
and IPX provide such a two part addressing scheme.
But protocols such as NetBEUI or LAT do not provide addressing at layer 3 and
therefore are unable to distinguish between different logical networks. As a
result they are not routable.
32. [CxNx] What is the default route on an IP network? Choose one.
a) This is the route that will be chosen first by IP for delivery of a datagram.
b) The address of the nearest downstream neighbor in a Token ring network.
c) At the router, it is the route used to direct frames for which the next hop has
not been explicitly listed in the routing table.
d) Any static route listing in a routing table.
e) When all conditions are equal, the best route for delivery of IP datagrams.
Answer
c) At the router, it is the route used to direct frames for which the next hop has
not been explicitly listed in the routing table.
The purpose of a default route is to route frames for which a next hop has not
been explicitly listed in the routing table. To say it another way is to say that
the default route points the way to go when there is no known path to follow. At
a router, the default route is the address of the next hop if no other route is
known or specified. Often the default route is set as a path to the Internet, where any unknown destination can hopefully be resolved.
33. [CxNx] A caret symbol (^) inserted into a failed command indicates which of
the following. Choose one.
a) Numeric data is required for this command.
b) The point in a command where you can simply press return to complete the syntax
string.
c) The point in a command where you have entered an incorrect command, keyword or
argument.
d) The point in a command where you must enter a required value.
e) This is a normal indicator for any failed command.
Answer
c) The point in a command where you have entered an incorrect command, keyword or
argument.
An example follows:
R2#sh clack
^% Invalid input detected at ^
marker.Router_B>sh cl?
WORD clock
34. [RXNx] The metric used by IPX RIP is:
【作者:本站编辑┊来源:培训资讯网┊2004-02-13】TAGS:
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