efi
ed


Tra
smissio
ofdataframe


Provideslogi
a
dlogoutprocedures


Selectsadesti
atio
etwork


Providesservicesforthe
etworkapplicatio
s


Reliablee
dtoe
ddatatra
smissio



fProvidesEmaila
dfiletra
sferservices


三、A
swerthefollowi
gquestio
s20：
（1）Pleaseshowa
exampleforeveryIPV4addressclasses5
A类地址范围0000127255255255
B类地址范围128000191255255255
C类地址范围192000223255255255
D类地址范围224000239255255255
E类地址范围240000255255255255
（2）Co
siderIPaddress20220320868Whatarethebroadcastaddressa
d
etworkaddresswhe
default
etworkmaskisused5broadcastaddress202203208255
etworkaddress2022032080
（3）Whataretheformata
dexampleofIPv6address5
4Co
siderplai
text“thisisatest”a
dtheCaesarcipherofk4isusedWhatistheCiphertextaftere
crypti
g5
四、Completefollowproblems35Supposewewa
ttotra
smitthemessage10101001a
dprotectitfromerrorsusi
gtheCRCge
eratorx31Uselo
gdivisio
todetermi
ethemessagethatshouldbetra
smitted（10）2Co
sideraCSMACD
etworkru
i
gat100Mbpsovera1000mcablewith
orepeatersThesig
alspeedi
thecableis2×108msecWhatisthemi
imumframesizeforcheckcollisio
reliably（10）
3SupposetwoEther
et
odesof10MbpsAa
dBareattachedtooppositee
dsofa900mcablea
dthereare4repeatersbetwee
Aa
dBIfthesizeofframeis1000bitsa
dthesig
alpropagatio
speedis2×108msa
deachrepeateri
serts20bitdelay151Whatistheo
ewaypropagatio
delayi
cludi
grepeaterdelaysbetwee
Aa
dBi
seco
d2Howlo
gtimeis
odeA’saframecompletelydeliveredat
odeB
五、Co
sideraLANshow
belowa
do
eclassCaddress20210024isavailableo
lyPleaseaccomplishthe
followi
gquestio
s15
Assig
IPNetwork
umbera
d
etmaskforallLANs
Assig
IPaddressestoall
etworki
terfaces
A
B
C
D
Determi
etheroutetable
o
routerR1
A
swer
（1）网络地址分配
网络
网络地址
HUB
R1
1
2
31
R2
网络掩码2
HUB
HUB
E
F
fA、B、R11C、D、R12R13、R21E、F、R22
（2）端口IP地址分配端口IP地址ABR11
端口IP地址CDR12R13
端口IP地址EFR22R21
（3）R1上的路由表
DestNetwork

extrouter
NhopsI
terface
计算机网络期末考试试题及答案计算机网络期末考试试题A卷填空题（每空1分，共30分）1、在计算机网络的定义中，一个计算机网络包含多台具有自治_功能的计算机；把众多计算机有机连接起来要遵循规定的约定和规则，即通信协议；计算机网络的最基本特征是__资源共享_______。2、常见的计算机网络拓扑结构有：总线型、星型r