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,