多选题You are troubleshooting an OSPF problem where external routes are not showing up in the OSPF database. Which two options a re valid checks that should be performed first to verify proper OSPF operation?（）AAre the ASBRs trying to redistribute the extern

第1题：

第2题：

When an OSPF design is planned, which implementation can help a router not have memory resource issues?（）

• A、Have a backbone area (area 0) with 40 routers and use default routes to reach external destinations
• B、Have a backbo ne area (area 0) with 4 routers and 30,000 external routes injected into OSPF
• C、Have less OSPF areas to reduce the need for interarea route summarizations
• D、Have multiple OSPF processes on each OSPF router. Example, router ospf 1, router ospf 2

第3题：

OSPF stub areas are an important tool for the Network designer； which of the following two shouldbe considered when utilizing OSPF stub areas？ （）

• A、 OSPF stub areas increase the size of the LSDB with the addition of Type 3 and 5 LSAs
• B、 OSPF not so stubby areas are particularly useful as a simpler form of summarization
• C、 OSPF stub areas are always insulated from external changes
• D、 OSPF totally stubby cannot distinguish among ABRs for the best route to destinationsoutsidethe areas
• E、 OSPF stub areas can distinguish among ASBRs for destinations that are external to the OSPFdomain

第4题：

You have implemented mutual route redistribution between OSPF and EIGRP on a border router. When checking the routing table on one o f the OSPF routers within the OSPF routing domain, you are seeing some, but not all of the expected routes. Which two things should you verify to troubleshoot this problem?（）

• A、The border router is using a proper seed metric for OSPF
• B、The border ro uter is using a proper seed metric for EIGRP
• C、The administrative distance is set for OSPF and EIGRP
• D、The missing EIGRP routes are present in the routing table of the border router
• E、The subnet keyword on the border router in the redistribute EIG RP command

第5题：

When attempting to view the OSPF routes in the routing table, you issue the command show route table inet.3 but no OSPF routes are displayed. What is the problem?（）

• A、The OSPF routes are located in the inet4.0 routing table.
• B、The OSPF routes are located in the inet.0 routing table.
• C、The OSPF routes are located in the inet.2 routing table.
• D、The OSPF routes are located in the inet4.3 routing table.

第6题：

Examine the following excerpt from the show ip eigrp topology 10.2.2.0/24 command on router R1.Which answer can be verified as definitely true based on this output?（） External data: Originating router is 10.1.1.1 AS number of route is 1 External protocol is OSPF, external metric is 64 Administrator tag is 0 (0x00000000)

• A、R1 is the router that redistributed the route
• B、R1's metric to reach subnet 10.2.2.0/24 is 64
• C、The route was redistributed on a router that has a router ospf 1 command configured
• D、R1 is redistributing a route to prefix 1 0.2.2.0/24 into OSPF

第7题：

Your MPLS implementation is currently using internal backdoor links. What can you do to minimize the impact of having these links？（）

• A、 use BGP as the CE-PE routing protocol
• B、 use OSPF as the CE-PE routing protocol
• C、 use EIGRP as the CE-PE routing protocol
• D、 use the SP to redistribute routes as external routes for OSPF and EIGRP
• E、 use route redistribution at each location to ensure external routes are imported into the IGP

第8题：

When attepting to view the OSPF routes in the routing table, you issue the command show route table inet but no OSPF routes are displayed. What is the problem?（）

• A、The OSPF routes are located in the inet 4 routing table
• B、THe OSPF routes are located in the inet 0 routing table
• C、The OSPF routes are located in the inet 2 routing table
• D、The OSPF routes are located in the inet 4.3 routing table

第9题：

第10题：

第11题：

第12题：

第13题：

You are troubleshooting an OSPF problem where external routes are not showing up in the OSPF database. Which two options a re valid checks that should be performed first to verify proper OSPF operation?（）

• A、Are the ASBRs trying to redistribute the external routes into a totally stubby area?
• B、Are the ABRs configured with stubby areas?
• C、Is the subnets keyword being used with the redistribution command?
• D、Is backbone area (area 0) contiguous?
• E、Is the CPU utilization of the routers high?

第14题：

OSPF external route哪些区域没有E1，E2类型的路由条目？

第15题：

You have completed an OSPF implementation, and you are verifying OSPF operation. During this verification, you notice that the OSPF route of 172.16.10.0 is repeatedly appearing and disappearing from the routing table. Further investigation finds that the OSPF CPU utilization is very high and the routers are constantly performing SPF calculations. You determine that 172.16.20.2 is the source of the 172.16.10.0 route. Using the show ip ospf database router 172.16.20.1 command, you notice that when this show command is performed repeatedly, the contents of the LSA change every few seconds. What could be the cause of this problem?（）

• A、OSPF authentication errors between some of the routers
• B、Two routers have the same OSPF router ID
• C、Issues with mistuned OSPF timers
• D、OSPF LSA pacing issues between some of the routers
• E、OSPF neighbor adjacency problems between some of the routers

第16题：

The OSPF External LSA for prefix x.x.x.x exists in the OSPF database， but the prefix is not installed in therouting table. Which are possible explanations？（）

• A、Inbound distribute-list is configured under the ospf process and it is denying x.x.x.x
• B、ASBR origination the LSA is not reachable
• C、Route to the Forwarding Address in not an internal OSPF route
• D、Route to the Forwarding Address is an internal OSPF route
• E、Route to the ASBR does not follow the same path as the one to the Forwarding Address

第17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.

第18题：

You have implemented mutua l route redistribution between OSPF and EIGRP on a border router. When checking the routing table on one of the EIGRP routers within the EIGRP routing domain, you are seeing some, but not all of the expected routes. What should you verify to troubleshoot this problem?（）

• A、The border router is using a proper seed metric for OSPF
• B、The border router is using a proper seed metric for EIGRP
• C、The administrative distance is set for OSPF and EIGRP
• D、The missing OSPF routes are present in the routing  table of the border router
• E、The subnet keyword on the border router in the redistribute OSPF command

第19题：

Router R1 sits inside OSPF area 1. Router R2 redistributes an E1 route into OSPF for prefix 2.2.2.0/24, with external metric 20. Router R22 redistributes an E2 route for the same prefix/length, external metric 10. Under what conditions will R1 choose as it s best route the route through R22?（）

• A、R1 will always choose the route through R22.
• B、As long as R1's best internal OSPF cost to reach R22 is less than 10.
• C、As long as R1's best internal OSPF cost to reach R22 is less than 20.
• D、R1 will never choo se the route through R22 if the E1 route through R2 is available.

第20题：

第21题：

第22题：

第23题：

第24题：