ACA Aruba Associate Routing Protocols 2 — Questions and Answers
Question 1: What does BGP stand for and where is it primarily used?
- Border Gateway Protocol; used between autonomous systems on the internet (Correct answer)
- Basic Gateway Protocol; used within a single enterprise campus
- Backup Gateway Protocol; used for redundant default routes
- Bridged Gateway Protocol; used for Layer 2 extensions
Correct answer: Border Gateway Protocol; used between autonomous systems on the internet
BGP is the path-vector routing protocol used between autonomous systems and is the routing protocol of the internet.
Question 2: What is the purpose of ECMP (Equal-Cost Multi-Path) routing?
- To load-balance traffic across multiple paths with equal routing metrics (Correct answer)
- To elect a primary and backup path for failover
- To summarize multiple subnets into a single route advertisement
- To prevent routing loops in distance-vector protocols
Correct answer: To load-balance traffic across multiple paths with equal routing metrics
ECMP allows a router to load-balance traffic across multiple equal-cost paths simultaneously, increasing throughput and redundancy.
Question 3: Which command on an Aruba CX switch shows the IP routing table?
- show ip route (Correct answer)
- show arp
- show vlan
- show lldp neighbors
Correct answer: show ip route
The show ip route command displays the IP routing table on Aruba CX switches, including route sources, metrics, and next-hops.
Question 4: What is route summarization (also called route aggregation)?
- Combining multiple specific routes into a single larger prefix to reduce routing table size (Correct answer)
- Splitting a large subnet into smaller ones for better management
- Distributing routes from one protocol into another
- Assigning multiple IP addresses to a single router interface
Correct answer: Combining multiple specific routes into a single larger prefix to reduce routing table size
Route summarization combines multiple contiguous specific routes into a single summary advertisement to reduce routing table size and LSA flooding.
Question 5: In OSPF, what triggers a Shortest Path First (SPF) recalculation?
- A change in the link-state database due to a new or changed LSA (Correct answer)
- A scheduled timer regardless of topology changes
- An administrator manually triggering the process
- A change in VLAN configuration
Correct answer: A change in the link-state database due to a new or changed LSA
OSPF triggers an SPF recalculation whenever the link-state database changes due to a new, updated, or withdrawn LSA from any router.
Question 6: What is the difference between a routing protocol and a routed protocol?
- A routing protocol exchanges routing information between routers; a routed protocol is the protocol whose traffic is being routed (Correct answer)
- A routing protocol carries user data; a routed protocol only manages router tables
- A routing protocol runs only on edge routers; a routed protocol runs on all devices
- A routing protocol uses UDP; a routed protocol uses TCP
Correct answer: A routing protocol exchanges routing information between routers; a routed protocol is the protocol whose traffic is being routed
A routing protocol like OSPF exchanges topology information between routers, while a routed protocol like IPv4 is the actual payload being forwarded.
ACA Aruba Associate Routing Protocols 2
What does BGP stand for and where is it primarily used?