| Exam 400-101 | Question id=760 | Layer 3 Technologies |
RouterA# show ipv6 ospf
Routing Process "ospfv3 10" with ID 10.2.3.4
SPF schedule delay 5 secs, Hold time between two SPFs 10 secs
Minimum LSA interval 5 secs. Minimum LSA arrival 1 secs
LSA group pacing timer 240 secs
Interface flood pacing timer 33 msecs
Retransmission pacing timer 66 msecs
Number of external LSA 0. Checksum Sum 0x000000
Number of areas in this device is 1. 1 normal 0 stub 0 nssa
Area 2
Number of interfaces in this area is 1
MD5 Authentication, SPI 1000
SPF algorithm executed 7 times
Number of LSA 0. Checksum Sum 0x000000
Number of DCbitless LSA 0
Number of indication LSA 0
Number of DoNotAge LSA 0
Flood list length 0
Which of the following statements are correct?
| A. |
RouterA is an ASBR | |
| B. |
RouterA is an ABR | |
| C. |
RouterA is an internal router | |
| D. |
RouterA is a backbone router | |
| E. |
RouterA is part of a stub area | |
| F. |
Router A is part of a totally stubby area | |
| G. |
RouterA is part of a standard area | |
| H. |
Route recalculation has occurred 7 times |
The output of the show ipv6 ospf command indicates that RouterA is an internal router, RouterA is part of a standard area, and route recalculation has occurred seven times. The output of the show ipv6 ospf command is similar to the show ip ospf command in that they both display the following information:
-Shortest path first (SPF) timer values and statistics
-Linkstate advertisement (LSA) timer values and statistics
-Number and type of areas in the router
-Whether authentication is enabled for an area
The router output Number of areas in this device is 1 indicates that there is only one Open Shortest Path First (OSPF) area in the router. Internal routers belong to a single OSPF area? therefore, RouterA is an internal router. The router output 1 normal 0 stub 0 nssa indicates that the area is a normal area, which is also called an ordinary or standard area. Therefore, RouterA is part of a standard area. Finally, the router output indicates that route recalculation has occurred seven times because the SPF algorithm has executed seven times on the router.
RouterA is not an autonomous system boundary router (ASBR). ASBRs connect two or more autonomous systems and redistribute routes between them. If RouterA were an ASBR, the output of the show ipv6 ospf command would display the line of text It is an autonomous system boundary router. In addition, the output would display the route sources that RouterA is redistributing into OSPF.
RouterA is not an area border router (ABR). ABRs connect two or more OSPF areas? a separate linkstate database (LSDB) is maintained for each area. If RouterA were an ABR, the output of the show ipv6 ospf command would display the line of text It is an area border device. In addition, the router output would indicate that multiple OSPF areas were configured on the router and statistical information would exist for each of those areas. In the output of the show ipv6 ospf command, statistical information exists only for Area 2.
RouterA is not a backbone router. A backbone router is a router with at least one interface in Area 0, the backbone area. The router output Area 2 indicates that RouterA is within Area 2, not Area 0. If RouterA were a backbone router, the output of the show ipv6 ospfcommand would display the line of text Area BACKBONE (0) instead of Area 2.
RouterA is not part of a stub area. A stub area is an area that does not accept Type 5 summary LSAs. If RouterA had at least one interface in a stub area, the output of the show ipv6 ospf command would indicate at least one stub area within the line of text 1 normal 0 stub 0 nssa. Additionally, if Area 2 were a stub area, the router output It is a stub area would appear within the statistical information for Area 2.
RouterA is not part of a totally stubby area. A totally stubby area is an area that does not accept Type 3, 4, or 5 summary LSAs. If RouterA had at least one interface in a totally stubby area, the output of the show ipv6 ospf command would indicate at least one stub area within the line of text 1 normal 0 stub 0 nssa. Additionally, if Area 2 were a stub area, the router output It is a stub area, no summary LSA in this area would appear within the statistical information for Area 2.