ACSP Routing Protocols & IP Addressing 2 — Questions and Answers
Question 1: An Aruba switch is running OSPF. Which LSA type is generated by an ABR to describe routes from one area to another?
- Type 1 - Router LSA
- Type 2 - Network LSA
- Type 3 - Summary LSA (Correct answer)
- Type 5 - AS External LSA
Correct answer: Type 3 - Summary LSA
ABRs generate Type 3 Summary LSAs to advertise inter-area routes between OSPF areas.
Question 2: What is the administrative distance of OSPF on an ArubaOS-CX switch by default?
- 90
- 110 (Correct answer)
- 120
- 170
Correct answer: 110
OSPF has a default administrative distance of 110 on ArubaOS-CX switches.
Question 3: Which OSPF network type does ArubaOS-CX assign to an interface configured as a point-to-point link?
- Broadcast
- Non-broadcast
- Point-to-point (Correct answer)
- Point-to-multipoint
Correct answer: Point-to-point
ArubaOS-CX assigns the point-to-point OSPF network type to interfaces connecting exactly two routers, eliminating DR/BDR election.
Question 4: A network engineer needs to prevent an ArubaOS-CX switch from becoming the OSPF DR on a broadcast segment. What is the most reliable method?
- Set the OSPF priority to 255
- Set the OSPF priority to 0 (Correct answer)
- Set the router-id to 0.0.0.0
- Disable OSPF hello packets
Correct answer: Set the OSPF priority to 0
Setting the OSPF interface priority to 0 makes the router ineligible for DR/BDR election.
Question 5: Which command on ArubaOS-CX verifies that OSPF neighbors have reached the FULL adjacency state?
- show ospf neighbors
- show ip ospf neighbor (Correct answer)
- show ospf interface
- show ip route ospf
Correct answer: show ip ospf neighbor
The 'show ip ospf neighbor' command displays neighbor states, including whether adjacency has reached FULL.
Question 6: An OSPF stub area is configured on an ArubaOS-CX switch. Which LSA type is blocked from entering the stub area?
- Type 1
- Type 2
- Type 3
- Type 5 (Correct answer)
Correct answer: Type 5
OSPF stub areas block Type 5 AS External LSAs, replacing external routes with a default route from the ABR.
Question 7: What does the OSPF cost metric on an ArubaOS-CX interface represent?
- Hop count to the destination
- The inverse of bandwidth on the link (Correct answer)
- The round-trip delay in milliseconds
- The number of routes in the routing table
Correct answer: The inverse of bandwidth on the link
OSPF cost is calculated as reference bandwidth divided by interface bandwidth, making it inversely proportional to link speed.
ACSP Routing Protocols & IP Addressing 2
An Aruba switch is running OSPF.
Which LSA type is generated by an ABR to describe routes from one area to another?