单选题What is a function of the OSPF Type 7 LSA？（）A It describes the reachability of routes in stub areas.B It describes the reachability of routes in totally-stubby areas.C It describes the reachability of routes in not-so-stubby areas.D It describes the re

第1题：

第2题：

The ASBR-summary LSA is：（）.

• A、Generated by the ASBR and describes reachability to itself
• B、Generated by the ASBR and describes reachabilty to the ABR
• C、Generated by the ABR and describes reachabilty to the ASBR for routers in a different area from the ASBR
• D、Generated by the ABR and describes reachabilty to the ASBR for routers in the same area with the ASBR

第3题：

第4题：

An OSPF non-backbone area follows external routes to be flooded within the area. These external routes are propagated into other areas. However， external routes from other areas are not allowed to enter this area. Which type of OSPF area does this describe？（）

• A、stub area
• B、transit area
• C、border area
• D、not-so-stubby area

第5题：

What is the function of the Type 4 LSA?（）

• A、Advertise cost to the ABR.
• B、Summarize external routes.
• C、Advertise cost to the ASBR.
• D、Report a broadcast segment's DR

第6题：

Which statement about OSPF ASBR summary LSA is true？（）

• A、It is generated by an ASBR and indicates the reachability to an ABR located in another area.
• B、It is generated by ABR and indicates the reachability to an ASBR located in another AS.
• C、It is generated by ABR and indicates reachability to itself.
• D、It is generated by ABR and indicates the reachability to an ASBR located in another area.
• E、It is generated by ASBR and indicates the reachability to an ABR.

第7题：

Which one of these statements is true of OSPF type 5 LSAs？ （）

• A、 They are used to summarize area routes to other areas.
• B、 They are used in not-so-stubby areas to propagate external routes.
• C、 They are used to notify areas of the ASBR.
• D、 They are flooded to all areas except stub areas （external route）.

第8题：

第9题：

An OSPF non-backbone area allows external routes to be flooded within the area. These external routes are propagated into other areas. However， external routes from other areas are not allowed to enter this area. Which type of SPF area does this describe？（）

• A、stub area
• B、transit area
• C、border area
• D、not-so-stubby area

第10题：

Which statement best describes OSPF external LSAs （type 5）？（）

• A、OSPF external LSAs are automatically flooded into all OSPF areas， unlike type 7 LSAs， which require that redistribution be configured.
• B、External LSAs （type 5） are automatically changed to type 1 LSAs at ASBRs.
• C、Type 5 LSAs are route summaries describing routes to networks outside the OSPF Autonomous System.
• D、External network LSAs （type 5） redistributed from other routing protocols into OSPF are not permitted to flood into a stub area.