JN0-1362 JNCDS-SP Practice Questions
Prepare for JN0-1362 with more than an answer.
- 1
CASE STUDY: A Service Provider has a legacy core running IS-IS and LDP. They are experiencing congestion on the shortest paths while alternate paths remain underutilized. They want to implement traffic engineering to balance loads without manually configuring explicit paths for every tunnel.
Requirement 1: Minimal configuration overhead.
Requirement 2: Dynamic adjustment to network state.
Requirement 3: Support for diverse path constraints.Which design approach best meets these requirements?
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Correct answer: A
RSVP-TE allows for traffic engineering away from the shortest path. The 'auto-bandwidth' feature allows LSPs to dynamically adjust their reserved bandwidth based on actual usage, and the CSPF algorithm will automatically move LSPs to alternate paths if the primary path is congested. This solves the congestion issue dynamically.
- 2
You are designing an Enterprise WAN connection for a customer who requires redundant connections to two different ISPs (multihoming). The customer wants to influence inbound traffic flow so that traffic prefers ISP A over ISP B. Which BGP attribute is the industry standard for influencing INBOUND traffic from upstream providers?
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Correct answer: A
AS Path Prepending is the standard method for influencing inbound traffic. By adding its own AS number multiple times to the AS Path advertised to the backup ISP (ISP B), the customer makes that path appear 'longer' and less desirable to the global internet, causing traffic to prefer the path via ISP A.
- 3
When designing a large-scale Route Reflector (RR) architecture for an MPLS core, you decide to implement a hierarchical design with top-level RRs and second-level RRs. What is the primary risk if the Cluster IDs are not configured correctly in this hierarchy?
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Correct answer: D
Cluster IDs are used by Route Reflectors to detect loops. If an RR receives a route with its own Cluster ID in the Cluster-List attribute, it discards the route. Incorrect configuration in a hierarchy can either cause loops (if IDs are missing/duplicate in wrong places) or unintentionally drop valid routes.
- 4
You are designing a Service Provider core network that requires fast reroute capabilities for MPLS Label Switched Paths (LSPs). The network must support strict bandwidth reservations and explicit path control. Which MPLS signaling protocol should you select for the primary LSP setup?
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Correct answer: C
RSVP-TE is the correct choice because it supports explicit path control, bandwidth reservation, and fast reroute (FRR) capabilities like link protection and node protection. LDP builds LSPs based solely on IGP metrics (shortest path) and does not natively support bandwidth reservations or explicit path engineering.
- 5
A customer requires a Layer 2 VPN service to connect three geographically dispersed sites. They need the ability to run their own Spanning Tree Protocol (STP) transparently across the service provider network without interaction with the provider's STP domains. Which service type best fits this requirement?
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Correct answer: B
VPLS provides a multipoint-to-multipoint Ethernet service that emulates a LAN. It transparently forwards Layer 2 frames, allowing the customer to run their own control plane protocols like STP across the WAN, as if the sites were connected to a single switch.
- 6
Which TWO statements regarding the 'fate-sharing' concept in network availability design are correct? (Select TWO)
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Correct answer: A, C
This is a classic definition of fate sharing; if the physical conduit is cut, both 'redundant' circuits fail simultaneously.
SRLGs allow the network designer to tag links that share physical resources (fate) so that signaling protocols like RSVP-TE can ensure primary and backup paths do not use links in the same group.
