| Exam 200-301 | Question id=5450 | IP Connectivity |
Examine the partial output from two adjacent routers:
RTR78# show ip ospf
Routing Process 201 with ID 192.0.2.1 VRF default
Stateful High Availability enabled
Graceful-restart is configured
Grace period: 60 state: Inactive
Last graceful restart exit status: None
Supports only single TOS(TCSO) routes
Supports opaque LSA
This router is an autonomous system boundary
Administrative distance 110
Reference Bandwidth is 40000 Mbps
Initial SPF schedule delay 3000.000 msecs,
minimum inter SPc delay of 2000.000 msecs,
maximum inter SPc delay of 4000.000 msecs
Initial LSA generation delay 3000.000 msecs
RTR79# show ip ospf
Routing Process 202 with ID 192.0.2.1 VRF default
Stateful High Availability enabled
Graceful-restart is configured
Grace period: 60 state: Inactive
Last graceful restart exit status: None
Supports only single TOS(TCSO) routes
Supports opaque LSA
This router is an autonomous system boundary
Administrative distance 110
Reference Bandwidth is 30000 Mbps
Initial SPF schedule delay 3000.000 msecs,
minimum inter SPF delay of 2000.000 msecs,
maximum inter SPF delay of 4000.000 msecs
Initial LSA generation delay 3000.000 msecs
Which of the following statements describes why the two routers are NOT forming an OSPF neighbor adjacency?
| A. |
The process IDs do not match | |
| B. |
The router IDs are misconfigured | |
| C. |
The distance is misconfigured | |
| D. |
The reference bandwidth does not match |
The output shows that the router IDs for RTR78 and RTR79 are the same value, which should not be the case. One of the two routers has been misconfigured with the other router's ID. This will prevent an OSPF neighbor adjacency from forming.
Other issues can that can prevent an adjacency are:
* Mismatched OSPF area number
* Mismatched OSPF area type
* Mismatched subnet and subnet mask
* Mismatched OSPF HELLO and dead timer values
The process IDs do not have to match. It does not matter whether they match or do not match because the process ID is only locally significant on the device.
The administrative distance is not misconfigured in the output. Both routers are using the default OSPF administrative distance of 110.
If the reference bandwidths do not match, it will affect the calculation of the path cost, but it will not prevent an adjacency from forming.