ccna interview questions and answers

Part - 12 CCNA Interview Questions and Answers

56 When the router runs out of buffer space, this is called ________.

A. Source Quench

B. Redirect

C. Information Request

D. Low Memory

Ans A

Source quench is the process where the destination router, or end internetworking device will "quench" the date from the "source", or the source router. This usually happens when the destination router runs out of buffer space to process packets.

57 Which protocol carries messages such as destination Unreachable, Time Exceeded,
Parameter Problem, Source Quench, Redirect, Echo, Echo Reply, Timestamp, Information Request, Information Reply, Address Request, and Address Reply?

A. ICMP

B. UDP

C. TCP

D. TFTP

E. FTP

Ans A

ICMP (Internet Control Message Protocol) is a network layer internet protocol described in RFC # 792. ICMP reports IP packet information such as destination Unreachable, Time Exceeded, Parameter Problem, Source Quench, Redirect, Echo, Echo Reply, Timestamp, Information Request, Information Reply, Address Request, and Address Reply.

58 Two of the protocols that can be carried in the Protocol field of an IP packet are?

A. TCP

B. UDP

C. FTP

D. TFTP

Ans A & B

The following are the fields in an IP segment, their length, and their definitions:
VERS (Version number - 16 bits)
HLEN (Number of 32-bit words in the header - 4 bits)
Type of Server (How the datagram should be handled - 32 bits)
Total Length (Total length of header and data - 32 bits)
Identification (Provide fragmentation of datagrams to allow different MTUs in the internet - 4 bits)
Flags (Provide fragmentation of datagrams to allow different MTUs in the internet - 4 bits)
Frag Offset (Provide fragmentation of datagrams to allow different MTUs in the internet - 6 bits)
TTL (Time-To-Live - 6 bits)
Protocol (Upperlayer protocol sending the datagram - 16 bits)
Header Checksum )Integrity check on the header - 16 bits)
Source IP Address (32 bits)
Destination IP Address (32 bits)
IP Options (network testing, debugging, security and others - 4 bits) Data (4 bits).

59 Where would network testing be included in an IP packet?

A. IP Options field

B. Identification field

C. Type of Service field

D. Reservation field

Ans A

60 What field tells the Internet layer how to handle an IP packet?

A. Type of Service

B. Identification

C. Flags

D. Frag Offset

Ans A