Cisco ENCOR Ultimate 5 — Questions and Answers
Question 1: Which multicast protocol is used between a multicast-capable router and directly connected hosts to manage group membership?
- PIM Sparse Mode
- IGMP (Internet Group Management Protocol) (Correct answer)
- MSDP (Multicast Source Discovery Protocol)
- DVMRP
Correct answer: IGMP (Internet Group Management Protocol)
IGMP operates between hosts and their directly connected routers to signal multicast group membership, enabling the router to know which groups have interested receivers.
Question 2: In PIM Sparse Mode, what is the role of the Rendezvous Point (RP)?
- It forwards all multicast traffic using dense flooding
- It serves as the meeting point where sources and receivers converge to build the multicast distribution tree (Correct answer)
- It assigns multicast IP addresses to sources
- It runs IGMP proxy for all connected hosts
Correct answer: It serves as the meeting point where sources and receivers converge to build the multicast distribution tree
The RP is a central router where PIM Sparse Mode sources register and receivers join, forming the shared distribution tree before switching to source-specific trees.
Question 3: A network engineer uses RESTCONF to retrieve device configuration. Which data format does RESTCONF natively support that NETCONF does not?
- XML
- JSON (Correct answer)
- YAML
- CSV
Correct answer: JSON
RESTCONF supports both XML and JSON encoding of YANG-modeled data, while NETCONF exclusively uses XML as its data encoding format.
Question 4: Which feature prevents a BGP router from advertising a route back to the neighbor from which it was learned, used primarily in iBGP to prevent routing loops?
- BGP Split Horizon (Correct answer)
- Route Reflector Client Rule
- BGP Next-Hop-Self
- AS_PATH Loop Detection
Correct answer: BGP Split Horizon
BGP Split Horizon (iBGP split horizon rule) prevents a router from readvertising iBGP-learned routes to other iBGP peers, requiring route reflectors or full mesh to overcome this.
Question 5: Which virtualization technology allows multiple logical router instances to share a single physical Cisco router platform, each with its own routing table and interfaces?
- VRF (Virtual Routing and Forwarding) (Correct answer)
- VXLAN
- GRE Tunneling
- MPLS LDP
Correct answer: VRF (Virtual Routing and Forwarding)
VRF creates separate virtual routing instances on a single physical router, each maintaining independent routing and forwarding tables for traffic isolation.
Question 6: What is the function of the 'ip sla' feature in Cisco IOS when combined with object tracking and a static route?
- It dynamically adjusts interface bandwidth based on traffic load
- It provides IP connectivity testing to conditionally install or remove a floating static route (Correct answer)
- It enables SNMP polling for interface statistics
- It configures NTP synchronization between routers
Correct answer: It provides IP connectivity testing to conditionally install or remove a floating static route
IP SLA probes test reachability to a target; when combined with object tracking, a tracked static route is removed from the routing table if the probe fails, triggering failover.
Question 7: Which 802.11 amendment introduced MU-MIMO (Multi-User MIMO) and operates in both 2.4 GHz and 5 GHz bands?
- 802.11n (Wi-Fi 4)
- 802.11ac (Wi-Fi 5)
- 802.11ax (Wi-Fi 6) (Correct answer)
- 802.11g
Correct answer: 802.11ax (Wi-Fi 6)
802.11ax (Wi-Fi 6) introduced both downlink and uplink MU-MIMO with up to 8 spatial streams, and operates across both 2.4 GHz and 5 GHz bands for improved dense-environment performance.
Cisco ENCOR Ultimate 5
Which multicast protocol is used between a multicast-capable router and directly connected hosts to manage group membership?