Chapter 4 The Network Layer
1．What is the name of a network-layer packet?（ ）
A. message
B. gment
C. datagram
D. frame
2．What are the two most important network-layer functions in a datagram network? （ ）
A. forwarding & routing
B. forwarding & filtering
C. routing & detecting
D. routing & checking
3．When a packet arrives at a router’s input link, the router must move the packet to the appropriate output link, this action is called ____? （ ）
A. Forwarding
B. routing
C. cut through
D. filtering
4．The network layer must determine the path taken by packets as they flow from a nder to a receiver. This action is called____? （ ）
A. Forwarding
B. routing
C. cut through
D. exa华山一日游攻略
mine
5．A router forwards a packet by examining the value of a field in the arriving packet’s header, and then using this value to index into the router’s forwarding table, this value is? （ ）
A. destination IP address
B. source IP address
C. destination MAC address
D. source MAC address
6．IP belongs to ____ layer? （ ）
A. transport
B. network
C. data link
D. physical
7．Which layer provides host-to-host rvices? （ ）
A. transport
B. network
C. data link
D. physical
8．Which layer provides a绿化草皮
connection rvice called virtual-circuit networks and a connectionless rvice called datagram networks? （ ）
A. transport
B. network
C. data link
D. physical
9．IPV4 has a ___ bit address? （ ）
A. 48
B. 16
C. 32
D. 64
10．MAC address is ____ bits? （ ）
A. 48
B. 16
C. 32
D. 64
11．The Internet’s network layer has three major components, the first component is the IP protocol, the c词语大全及解释
ond component is the routing protocol, the final component is____? （ ）
A. forwarding
B. address translation
C. check
D. ICMP
12．How many bits specify the IP protocol version in a datagram? （ ）
A. 1 bit
B. 2 bits
C. 4 bits
D. 8 bits
13．Most IPV4 datagram do not contain option field, how many bytes a header has in a typical IP datagram? （ ）
A. 4 bytes
B. 8 bytes
C. 16 bytes
D. 20 bytes
14．How many bits ud in IP datagram express total length of the IP datagram? （ ）
A. 4 bits
B. 8 bits
C. 16 bits
D. 20 bits
15．Data-grams are rarely larger than ____?（ ）
A. 1500 bytes
B. 65535 bytes
C. 500 bytes
D. 1024 bytes
16．New version of IP----IPV6 does not allow fragment in ____?（ ）
A. Router
B. Host
C. Both of above
D. None of above
17．How does the TTL changed by one each time the datagram is procesd by a router? （ ）
A. decrea
