JN0-364 Service Provider Routing and Switching, Specialist (JNCIS-SP) Practice Questions
Prepare for JN0-364 with more than an answer.
- Time limit
- 90 minutes
- Questions on the exam
- 65
- Level
- Specialist
- Valid for
- 3 years
Domains covered on the exam 10
- Protocol-Independent Routing10%
- Open Shortest Path First (OSPF)10%
- Intermediate System to Intermediate System (IS-IS)10%
- Border Gateway Protocol (BGP)10%
- Layer 2 Bridging or VLANs10%
- Spanning-Tree Protocols10%
- Multiprotocol Label Switching (MPLS)10%
- IPv610%
- Tunnels10%
- High Availability10%
- 1
In an IS-IS routing domain, which Protocol Data Unit (PDU) is responsible for describing the entire contents of the Link-State Database (LSDB) to ensure synchronization between routers on a broadcast segment?
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Correct answer: C
The Complete Sequence Number PDU (CSNP) contains a summary of all LSPs in the router's LSDB. On a broadcast network, the DIS periodically multicasts CSNPs to ensure all routers have a synchronized database. If a router notices a missing or outdated LSP based on the CSNP, it will request the specific LSP using a PSNP (Partial Sequence Number PDU).
- 2
Which TWO statements correctly describe the behavior of IS-IS Level 1 and Level 2 routing in a multi-area network? (Select TWO)
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Correct answer: B, C
In IS-IS, an L1/L2 router acts as a border between the L1 area and the L2 backbone. By default, it sets the Attached (ATT) bit in its L1 LSP. When L1-only routers see this ATT bit, they automatically generate a default route pointing to the nearest L1/L2 router. IS-IS does not automatically leak L2 routes into L1 (this prevents routing loops and limits L1 database size); route leaking requires an explicit routing policy.
- 3
A service provider is migrating their IS-IS backbone to support traffic engineering and higher link metrics. The engineers configure 'wide-metrics-only' under the IS-IS hierarchy.
Which combination of TLVs will the routers use to advertise reachability and IP prefixes after this change?
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Correct answer: B
When 'wide-metrics-only' is configured, IS-IS stops using the legacy narrow metric TLVs (TLV 2 for IS neighbors and TLV 128/130 for IP reachability), which only support a 6-bit metric (max 63). Instead, it exclusively uses the newer TLV 22 (Extended IS Reachability) and TLV 135 (Extended IP Reachability), which provide a 24-bit metric space (up to 16,777,215) and support sub-TLVs required for MPLS Traffic Engineering.
- 4
A service provider engineer needs to leak interface routes from the default routing table (inet.0) to a custom routing instance table named 'cust-A.inet.0'. Which configuration snippet correctly utilizes a RIB group to achieve this objective?
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Correct answer: B
To leak interface routes between routing tables, a RIB group must be created specifying the primary and secondary routing tables using the 'import-rib' statement. The primary table (inet.0) is listed first, followed by the secondary table (cust-A.inet.0). This RIB group is then applied globally under the [edit routing-options interface-routes] hierarchy to instruct the router to place direct interface routes into both tables.
- 5
A large enterprise customer requires traffic engineering based on source IP address and application type. The architect decides to implement Filter-Based Forwarding (FBF) on the ingress Junos device.
The requirements are:
- HTTP traffic from subnet 10.1.1.0/24 must be routed to ISP-1.
- All other traffic must follow the standard default route to ISP-2.
- The design must minimize impact on the global routing table.
Which combination of configuration elements is required to successfully implement this FBF architecture?
flowchart TD Ingress([Ingress Traffic]) --> Filter{Firewall Filter} Filter -->|Match HTTP| FBF[FBF Routing Instance] Filter -->|No Match| Default[inet.0 Default Table] FBF --> ISP1[Next-Hop ISP 1] Default --> ISP2[Next-Hop ISP 2]Show answer details
Correct answer: C
Filter-Based Forwarding (FBF) relies on a firewall filter applied to the ingress interface. The filter evaluates traffic and uses the 'then routing-instance' action for matched packets, directing them to a custom routing instance. To isolate this forwarding plane without creating full virtual routers, the instance is typically configured as 'instance-type forwarding' and populated with the necessary next-hop routes (e.g., pointing to ISP-1). Traffic not matching the filter falls through to the global routing table (inet.0).
- 6
When comparing aggregate and generated routes in Junos OS, which TWO statements accurately describe their characteristics? (Select TWO)
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Correct answer: B, C
Both aggregate and generated routes are used to summarize routing information. By default, an aggregate route is assigned a next-hop of reject (or discard, depending on configuration), preventing routing loops for subnets within the summary that do not exist. Conversely, a generated route can inherit the real next-hop of the primary contributing route, allowing it to forward traffic dynamically.
