Mời trao đổi một số câu hỏi ôn tập CCNA

[titanevn]

27. Contoso.com has allocated the IP add 199.144.27.0 is its network, to provide flexibility for the LAN design, a subnet mask of 255.255.255.240 has been chosen. Which of the following address can be assigned to LAN on the resulting subnets (Choose three)

A. 199.141.27.33
B. 199.141.27.112
C. 199.141.27.119
D. 199.141.27.126
E. 199.141.27.175
F. 199.141.27.208

B --> Subnet ID --> bỏ
E --> Broadcast --> bỏ
F --> Subnet ID --> bỏ

Còn lại: A,C,D --> đáp án là A,C,D

[cacodemon]

Re: Mời trao đổi một số câu hỏi ôn tập CCNA (part I)

Giúp em câus này nha
1. When a host receives a data segment, what allows the host to determine which application should receive the segment?
A. IP source address
B. IP destination address
C. PAR
D. sliding window
E. port number
F. SYN packet
Answer: F

2. What is the purpose of the three-way handshake that occurs between hosts using TCP as the transport layer protocol?

A. to determine the number of packets that can be sent before an acknowledgment is required
B. to allow a host to forward data to a router
C. to establish a round trip connection between sender and receiver before data is transferred
D. to provide a mechanism for data encryption and compression
Answer: C

3.Which of the following describes how TCP adds reliability to communication? (Choose two.)

A. Hosts using TCP set up virtual circuits at the beginning of the transmission using the three-way handshake.
B. Hosts using TCP set the error-checking frequency at the beginning of the transmission and maintain this frequency for the duration.
C. The receiving host acknowledges that it has received the expected number of segments and requests additional data.
D. The receiving host acknowledges any incorrectly received data and requests retransmission of damaged or missing bytes
Answer: A & D

4.What is used by UDP to determine if the data or header has been transferred without corruption?

A. lower layer protocols
B. checksum
C. PAR
D. sliding window
E. acknowledgment and retransmission
F. IP
Answer: B

5.What is the purpose of Positive Acknowledgment and Retransmission (PAR)?

A. PAR allows the presentation layer to request that data be resent in a format the destination host can process.
B. PAR provides a mechanism for the receiving device to request that all segments be retransmitted if one segment is corrupt.
C. PAR helps ensure that a number of data segments sent by one host are received by another host before additional data segments are sent.
D. PAR is used to renegotiate the window size during the synchronization process
Answer: C

[admin]

Re: Mời trao đổi một số câu hỏi ôn tập CCNA (part I)

1. Port sẽ xác định ứng dụng nào sử dụng data segment. Do đó, để xác định ứng dụng nào (applications) dùng một data segment, cần xem port được chứa trong header của segment đó. Do đó, câu 1 bạn nên chọn E

3. Host nhận sẽ ACK những segments mà nó nhận đúng. Do đó bạn nên chọn A và C

Thân chúc cacodemon học giỏi,

[cacodemon]

Re: Mời trao đổi một số câu hỏi ôn tập CCNA (part I)

:P Cám ơn Admin nhiều nhiều, hỏi nữa nha.
1. Which statement is true regarding the TCP protocol?

A. Flow control at the transport layer is provided by adding a sequence number to each segment.
B. A sliding window allows for communicating devices to negotiate the amount of unacknowledged data that can be sent.
C. A window size of 1 would require a receiving device to send ACK 1 after the Segment 1 has been received.
D. TCP is used by sending hosts to segment large data files prior to transmission while IP is used by receiving host to reassemble the smaller segments.
Answer: C
2. How are originating source port numbers assigned during the data encapsulation process?

A. assigned manually by the user when starting the application
B. assigned dynamically by the source host
C. assigned by the routing protocol during the lookup process
D. assigned by the destination host during session negotiation
Answer: B

3. What is the purpose of using port numbers in the transport layer?

A. to identify the segment as being either TCP or UDP
B. to provide reliability during data transport
C. to identify the interface port number used by the router when forwarding data
D. to track multiple conversations that occur between hosts
Answer: D

4. During the encapsulation process, in which order are the IP address, MAC address, and port number assigned when the router is establishing communication with the TFTP server?

A. IP address, MAC address, port number
B. MAC address, IP address, port number
C. port number, IP address, MAC address
D. port number, MAC address, IP address
Answer: B or D câu này em quên rồi

5. Which transport layer unit of information places the port number in the header?

A. data
B. segment
C. packet
D. frame
E. bit
Answer: E

6. Soure port:1406 Destination port:80 Sequence#:2563987 ACK#:4679 Window:8192 Data
What type of segment and data is shown in the graphic?

A. a UDP segment carrying e-mail traffic
B. a TCP segment carrying FTP traffic
C. an IP segment carrying FTP traffic
D. a UDP segment carrying web traffic
E. a TCP segment carrying web traffic
F an IP segment carrying e-mail traffic
Answer: E
7. Which of the following describes a type of denial of service attack designed to exploit the normal function of the TCP three-way handshake?

A. A host sends a packet with a spoofed source IP address.
B. A host sends a packet with an incorrect destination IP address.
C. A source sends a packet containing a garbled header.
D. A host sends an oversized packet that fills the memory buffers of the destination host.
E. A host sends a packet that contains a virus.
F. A host sends a packet that contains a worm.
Answer: A

8. At which point in the transmission process are segments numbered?

A. when received
B. when reassembling
C. before transmission
D. while negotiating window size
Answer: C
:lol:

[danguyennhi]

4. Thứ tự xử lý là port number, IP address, MAC addresses. Do đó C.
5. B segment đặt port-number trong header

[cacodemon]

Re: Mời trao đổi một số câu hỏi ôn tập CCNA (part I)

1. Which statement is true regarding wildcard masks?

A. The wildcard mask and subnet mask perform the same function.
B. The wildcard mask is always the inverse of the subnet mask.
C. A "0" in the wildcard mask identifies IP address bits that must be checked.
D. A "1" in the wildcard mask identifies a network or subnet bit.
Answer: C
2. Which of the following describe types of port numbers that can be represented in the header of TCP and UDP segments? (Choose two)
A. connectionless
B. well-known
C. operational
D. dynamic
E. static
Answer: A & D

3.

access-list 147 deny tcp 172.16.0.0 0.0.255.255 any eq 23
access-list 147 permit ip any any

Assuming the ACL in the graphic is correctly applied to an interface, what effect will the ACL have on network traffic?

A. All traffic to network 172.16.0.0 will be denied.
B. All TCP traffic will be permitted to and from network 172.16.0.0.
C. All telnet traffic from the 172.16.0.0 network to any destination will be denied.
D All port 23 traffic to the 172.16.0.0 network will be denied.
E. All traffic from the 172.16.0.0 network will be denied to any other network.
Answer: D
4.

access-list 120 deny tcp host 192.168.15.4 any eq 21

Assuming the ACL in the graphic is correctly applied to an interface, what effect will this ACL have on network traffic?

A. Host 192.168.15.4 will be denied ftp access to any destination, but will be permitted all other access.
B. All ftp traffic to host 192.168.15.4 will be denied.
C. All traffic from that interface will be denied.
D. No traffic will be denied because a "permit" statement does not exist in this ACL.
Answer : C

5. Select the correct statements about extended ACLs. (Choose two)

A. Extended ACLs use a number range from 1-99.
B. Extended ACLs end with an implicit permit statement.
C. Extended ACLs evaluate the source and destination addresses.
D. Port numbers can be used to add greater definition to an ACL.
E. Multiple ACLs can be placed on the same interface as long as they are in the same direction.
Answer : B, C, E

[cacodemon]

4. Thứ tự xử lý là port number, IP address, MAC addresses. Do đó C.
5. B segment đặt port-number trong header

:Fade-col: Thanks you very much.

[Nokia6610]

Hi Danguyennhi.
Bạn có thể giải thích vì sao chọn C không ?
Theo mình biết, OSPF ra đời sau 2 chú RIP, IGRP nên việc tăng Overhead over network là đúng. ( OSPF xài loại Router yêu cầu xịn hơn)

Có ai có ý khác không nhỉ .?

[Jindo]

trả lời bài test này như thế nào nhỉ?

các bạn ơi cho mình hỏi trả lời bài test này như thế nào nhỉ?(xem file đính kèm)
cám ơn nhiều

[minhchi]

b,e,f

[nth14026]

Re: trả lời bài test này như thế nào nhỉ?

Bạn chọn câu: B, E và F nha.

Thân chào

Bye bye
N.T.H

[Jindo]

các bạn co thể giải thích cho mình được không ?
Thanks,.

[nth14026]

Re: trả lời bài test này như thế nào nhỉ?

Bạn ơi !

Câu hỏi này liên quan đến phần chia IP Subnet. Bạn tham khảo trong giáo trình ICND đó.

Thân

[daredevilk]

Re: trả lời bài test này như thế nào nhỉ?

Hình của bạn đưa sai rồi.
Vì 192.168.82.90 là lớp C do đó nó phải có tổng số bít >=24 mà hình lại cho là 20 là sai.Bạn xem lại coi
Do đó chỉ có 2 câu đúng thôi.

[NgHanh]

cái đó kô liên quan tới câu hỏi. người ta nói tìm broadcast add thì cứ coi trong đống câu trả lời, cái nào là broad add thì chọn thui.