JN0-352 Enterprise Routing and Switching, Specialist (JNCIS-ENT) exam
Proctored multiple-choice knowledge exam mapped to the published Juniper objectives and the current software scope named on the official page.
- Type
- Written
- Delivery
- Both
- Duration
- 90 min
- Questions
- 65
Exam sections
Layer 2 Switching or VLANs
Layer 2 Switching or VLANs brings together Identify the concepts, operations, or functionalities of Layer 2 switching for the Junos OS: Bridging components Frame processing Describe the concepts, benefits, or functionalities of VLANs: Ports Tagging Native VLANs and voice VLANs Inter-VLAN routing Demonstrate knowledge how to configure, monitor, or troubleshoot Layer 2 switching or VLANs: Interfaces and ports VLANs Inter-VLAN routing. The section matters because it tests whether candidates can translate official product knowledge into defensible choices for realistic enterprise routing and switching design, implementation, operations, and troubleshooting scenarios. For JNCIS-ENT, the practical connection to Spanning Tree is especially worth tracing.
Question notes
Expect the assessment to probe distinctions between closely related options and to place Layer 2 Switching or VLANs inside scenarios where requirements determine the best response. This distinction matters specifically to Enterprise Routing and Switching, Specialist (JNCIS-ENT) exam and its role-focused assessment boundary.
Preparation tips
Build a small scenario around Layer 2 Switching or VLANs, perform or diagram the relevant workflow, then explain why each choice is appropriate and what evidence would reveal a mistake. Use the official subtopics as a checklist after the exercise. Keep the final notes organized under Layer 2 Switching or VLANs so gaps remain traceable to the published outline.
Spanning Tree
Spanning Tree examines Describe the concepts, benefits, operations, or functionalities of the Spanning Tree Protocol (STP): STP and Rapid Spanning Tree Protocol (RSTP) concepts Port roles and states Bridge Protocol Data Units (BPDUs) Convergence and reconvergence Demonstrate knowledge how to configure, monitor, or troubleshoot Spanning Tree: STP RSTP. Candidates should be able to connect these elements to enterprise routing and switching design, implementation, operations, and troubleshooting and recognize how decisions in this area affect the surrounding Junos OS and Juniper networking platforms solution. For JNCIS-ENT, the practical connection to Layer 2 Security is especially worth tracing.
Question notes
Some prompts begin with an observed result and ask for the most likely cause or next action. Practice separating evidence from assumptions before selecting an answer about Spanning Tree. A correct response should address the whole requirement without introducing conflict elsewhere in the JNCIS-ENT scope.
Preparation tips
Use the official outline to design several decision scenarios for Spanning Tree. For each one, state the requirement, reject at least one tempting alternative, and justify the final approach in product-specific terms. Then connect the exercise to Layer 2 Security so preparation covers the handoff between domains.
Layer 2 Security
Candidates encounter Identify the concepts, benefits, or operations of various Layer 2 protection or security features: BPDU, loop or root protection Port security, including MAC limiting, DHCP snooping, Dynamic ARP inspection (DAI) or IP source guard MACsec Storm control Identify the concepts, benefits, or operations of Layer 2 firewall filters: Filter types Processing order Match criteria and actions Demonstrate knowledge how to configure, monitor, or troubleshoot Layer 2 security: Protection Port security Storm control Firewall filter configuration and application in the Layer 2 Security domain. The section links platform knowledge to practical consequences, including dependencies, trade-offs, validation methods, and recoverable failure conditions. The expected depth is the depth needed to support enterprise routing and switching design, implementation, operations, and troubleshooting, not merely define the listed terms.
Question notes
Candidates should be ready for prompts that connect more than one objective, especially where Layer 2 Security influences security, availability, performance, governance, or supportability. Treat the published outline for Enterprise Routing and Switching, Specialist (JNCIS-ENT) exam as the limit on product detail the prompt can reasonably require.
Preparation tips
Pair official reading with retrieval practice: close the material, reconstruct the Layer 2 Security workflow, and check the result against the blueprint. Record gaps by subtopic instead of repeatedly rereading the entire section. Retest the same skill from an operator, designer, or customer perspective that matches JNCIS-ENT.
Protocol Independent Routing
Coverage in Protocol Independent Routing includes Identify the concepts, operations, or functionalities of various protocol-independent routing components: Static, aggregate, and generated routes Martian addresses Routing instances, including routing information base (RIB) groups Load balancing Filter-based forwarding Demonstrate knowledge how to configure, monitor, or troubleshoot various protocol-independent routing components: Static, aggregate, and generated routes Load balancing Filter-based forwarding. Candidates should understand both the intended workflow and the signals that indicate a design, configuration, analysis, or operational approach is not working as expected. The domain is most useful when studied as part of the complete JNCIS-ENT workflow.
Question notes
Questions in this area may combine conceptual recognition with applied judgment, asking candidates to interpret a condition, select an approach, or identify the consequence of a change. A correct response should address the whole requirement without introducing conflict elsewhere in the JNCIS-ENT scope.
Preparation tips
Review Protocol Independent Routing from both a builder's and an operator's perspective. Ask how it is planned and configured, then how its health, security, performance, and failure state are observed. Repeat the exercise with a changed requirement to test whether the reasoning transfers beyond one memorized case.
OSPF
OSPF brings together Describe the concepts, operations, or functionalities of OSPF: Link-state database OSPF packet types Router ID Adjacencies and neighbors Designated router (DR) and backup designated router (BDR) OSPF area and router types Realms Link-state advertisement (LSA) packet types Demonstrate knowledge how to configure, monitor, or troubleshoot OSPF: Areas, interfaces, and neighbors Additional basic options Routing policy application Troubleshooting tools (ping, traceroute, traceoptions, show commands, logging). The section matters because it tests whether candidates can translate official product knowledge into defensible choices for realistic enterprise routing and switching design, implementation, operations, and troubleshooting scenarios. That context distinguishes OSPF knowledge from generic familiarity with Junos OS and Juniper networking platforms.
Question notes
This area rewards precise reading: plausible distractors often describe a valid feature used in the wrong layer, sequence, role, or operating condition. This distinction matters specifically to Enterprise Routing and Switching, Specialist (JNCIS-ENT) exam and its role-focused assessment boundary.
Preparation tips
Create a one-page map linking OSPF to Junos OS and Juniper networking platforms components, dependencies, inputs, and outcomes. Then test the map with realistic constraints and failure cases drawn from your own lab or project experience. Repeat the exercise with a changed requirement to test whether the reasoning transfers beyond one memorized case.
IS-IS
In this part of the assessment, candidates work with Describe the concepts, operations, or functionalities of IS-IS: Link-state database IS-IS Protocol Data Units (PDUs) Type, length, and values (TLVs) Adjacencies and neighbors Levels and areas Designated intermediate system (DIS) Metrics Demonstrate knowledge of how to configure, monitor, or troubleshoot IS-IS: Levels, interfaces, and adjacencies Additional basic options Routing policy application Troubleshooting tools (ping, traceroute, traceoptions, show commands, logging). The emphasis is on usable understanding: selecting, explaining, implementing, or troubleshooting the relevant Junos OS and Juniper networking platforms behavior in context. In Enterprise Routing and Switching, Specialist (JNCIS-ENT) exam, the topic belongs to a broader assessment of enterprise routing and switching design, implementation, operations, and troubleshooting.
Question notes
This area rewards precise reading: plausible distractors often describe a valid feature used in the wrong layer, sequence, role, or operating condition. The strongest answer should remain consistent with the wider goal of enterprise routing and switching design, implementation, operations, and troubleshooting.
Preparation tips
Make a table of common IS-IS symptoms, likely causes, decisive evidence, and corrective actions. Use it to work through short incidents until diagnosis follows evidence rather than pattern matching. Add a validation step that would convince another Junos OS and Juniper networking platforms practitioner the outcome is correct.
BGP
BGP examines Describe the concepts, operations, or functionalities of BGP: BGP basic operation BGP message types Attributes Route/path selection process Internal and external BGP (IBGP and EBGP) functionality and interaction Demonstrate knowledge of how to configure, monitor, or troubleshoot BGP: Groups and peers Additional basic options Routing policy application Troubleshooting tools (ping, traceroute, traceoptions, show commands, logging). Candidates should be able to connect these elements to enterprise routing and switching design, implementation, operations, and troubleshooting and recognize how decisions in this area affect the surrounding Junos OS and Juniper networking platforms solution. Its place in JNCIS-ENT becomes clearer when candidates follow inputs and outcomes into Tunnels.
Question notes
Candidates should be ready for prompts that connect more than one objective, especially where BGP influences security, availability, performance, governance, or supportability. When context is ambiguous, prefer the interpretation that fits Junos OS and Juniper networking platforms guidance and the stated scenario outcome.
Preparation tips
Practice troubleshooting from symptoms related to BGP. Form a hypothesis, identify the most useful evidence, choose a corrective action, and verify the expected result so preparation mirrors operational reasoning. Add a validation step that would convince another Junos OS and Juniper networking platforms practitioner the outcome is correct.
Tunnels
The official outline places Identify the concepts, requirements, or functionalities of IP tunneling: Tunneling applications and considerations Generic Routing Encapsulation (GRE) IP-IP Demonstrate knowledge of how to configure, monitor, or troubleshoot IP tunnels: GRE IP-IP Troubleshooting tools (ping, traceroute, traceoptions, show commands, logging) within Tunnels. Candidates need to understand how the pieces relate, when each one is relevant, and what a sound result looks like in the context of Junos OS and Juniper networking platforms. In Enterprise Routing and Switching, Specialist (JNCIS-ENT) exam, the topic belongs to a broader assessment of enterprise routing and switching design, implementation, operations, and troubleshooting.
Question notes
The assessment may connect configuration intent with resulting behavior. Candidates should understand how changes in Tunnels become visible through status, telemetry, policy evaluation, or user experience. Cross-check the proposed answer against dependencies that connect Tunnels with High Availability.
Preparation tips
Create a one-page map linking Tunnels to Junos OS and Juniper networking platforms components, dependencies, inputs, and outcomes. Then test the map with realistic constraints and failure cases drawn from your own lab or project experience. Finish by checking the result against every official subtopic grouped under Tunnels.
High Availability
High Availability examines Identify the concepts, benefits, applications, or requirements for high availability in a Junos OS environment: Link aggregation groups (LAG) Redundant trunk groups (RTG) Virtual chassis Graceful restart Graceful Routing Engine switchover (GRES) Nonstop active routing (NSR) Nonstop bridging (NSB) Bidirectional Forwarding Detection (BFD) Virtual Router Redundancy Protocol (VRRP) Unified In-Service Software Upgrade (ISSU) Demonstrate knowledge of how to configure, monitor, or troubleshoot high availability components: LAG and RTG Virtual chassis Graceful. Candidates should be able to connect these elements to enterprise routing and switching design, implementation, operations, and troubleshooting and recognize how decisions in this area affect the surrounding Junos OS and Juniper networking platforms solution. Its place in JNCIS-ENT becomes clearer when candidates follow inputs and outcomes into Layer 2 Switching or VLANs.
Question notes
Coverage can test both what High Availability does and when it is the appropriate choice. Be prepared to reject solutions that are technically possible but misaligned with the stated goal. Anchor your response in the High Availability scope published for Enterprise Routing and Switching, Specialist (JNCIS-ENT) exam.
Preparation tips
Practice troubleshooting from symptoms related to High Availability. Form a hypothesis, identify the most useful evidence, choose a corrective action, and verify the expected result so preparation mirrors operational reasoning. Use mistakes from the exercise to create a focused revision list for Enterprise Routing and Switching, Specialist (JNCIS-ENT) exam.