Hcip137-147 title + analysis

137、OSPF Agreement , It can't just be based on LS Sequence Number and LS age To judge the same LSA How old and new

A、 Yes TRUE

B、 wrong FALSE

right key ：A

analysis : stay OSPF Protocol comparison LSA New and old , We will compare LSA The serial number of 、 Survival time 、 Checksums fields . If it's all the same ,

It is considered to be the same LSA . So the description in the title is correct .

138、OSPF Yes 5 Message type , Please match the message with the function ( Drag and drop questions )

A、Hello message ： Discover and maintain adjacency

B、DD message ： Interactive link database summary information

C、LSR message ： Request specific contact information

D、LSU message ： Detailed link state information occurs

E、LSAck message : Send a confirmation message

right key ：ABCDE

analysis : This topic is called connecting question , Remember the correspondence of each option

139、OSPF There are many message types , Where specific link state information is requested from neighbors , Which message should be used ?

A、Database Description

B、Link State Request

C、Link State Acknowledge

D、Link State Update

E、Hello

right key ：B

141、OSPF Support multiple processes , You can run multiple different OSPF process , They don't affect each other , each other
Independent and different OSPF The routing interaction between processes is equivalent to the routing interaction between different routing protocols
A、 Yes TRUE
B、 wrong FALSE
right key ：A
142、OSPF Support multiple authentication methods , Including plaintext authentication 、md5 Certification and hmac-md5 Certification, etc
A、 Yes TRUE
B、 wrong FALSE
right key ：A
143、OSPF Which of the following default routing methods are supported ? ( multi-select )
A、 Can be in ABR Up and down
B、 Can be in ASBR Up and down
C、 Can only be forced to issue
D、 It can be issued without compulsion

right key ：ABD
analysis : stay OSPF Agreement , There are many ways to generate default routes . Can pass 3 class LSA In the form of , It can also be done through 5 class LSA In the form of . If it's through
too 3 class LSA In the form of , So in ABR on . If it is 5 class LSA If so, right here ASBR produce , It can be enforced , It can also be done through
Non mandatory method . So the correct answer is “ Can be in ABR Up and down ”、“ Can be in ASBR Up and down ”、“ It can be issued without compulsion ”

144、OSPF Only in Hello There is verification information in the message ,OSPF Support MD5 Ciphertext verification
A、 Yes TRUE
B、 wrong FALSE
right key ：B
145、OSPF Run directly on IP The agreement above , The use of IP The agreement number is 89.
A、 Yes TRUE
B、 wrong FALSE
right key ：A
146、OSPF Run directly on TCP The agreement above , Use TCP Port number 179
A、 Yes TRUE
B、 wrong FALSE
right key ：B
analysis :OSPF The agreement belongs to OSI The third layer of the model , Directly encapsulated in IP Behind the head , The agreement number is 89. So the description in the title is wrong
147、OSPF in , Elected in broadcast type networks DR and BDR, Both listening 224.0.0.5 Address , And listen to 224.0.0.6
Address
A、 Yes TRUE
B、 wrong FALSE
right key ：A
analysis : about OSPF Of DR/BDR for , They are ordinary OSPF Router , So we must monitor 224.0.0.5 , At the same time, all other routers send database updates , Must be given at the same time DR/BDR , therefore DR/BDR And monitor at the same time 224.0.0.6 . So the description in the title is correct .