Juniper JN0-352 Real Exam Dumps [August 2026 Update]

The high availability section of the JN0-352 exam trips more candidates than any other single topic area, and the reason is almost always the same: VRRP, GRES, and NSR are treated as interchangeable terms for “backup routing.” They are not interchangeable. They solve three completely different problems. VRRP (Virtual Router Redundancy Protocol) provides gateway redundancy for end hosts – when the primary gateway fails, hosts continue forwarding through the backup without reconfiguring their default route. GRES (Graceful Routing Engine Switchover) preserves forwarding table state on the line cards during a Routing Engine switchover – traffic continues flowing during the RE failover, but routing protocol neighbors see the adjacency drop and reconverge. NSR (Nonstop Active Routing) goes further than GRES: it preserves both the forwarding table and the routing protocol state, so neighbors do not see the switchover at all and do not reconverge. A question that asks which mechanism prevents OSPF neighbors from detecting a Routing Engine failover is asking for NSR, not GRES, not VRRP. Getting this right requires understanding what each mechanism preserves and what it leaves to reconvergence.

The Juniper JN0-352 (Enterprise Routing and Switching, Specialist, JNCIS-ENT) is the specialist-level certification in Juniper’s Enterprise track, validating intermediate knowledge of enterprise network routing and switching using Junos OS. It was updated June 8, 2026 with a refreshed exam. Prerequisites: JNCIA-Junos active certification. The exam is 65 multiple-choice questions in 90 minutes, delivered through Pearson VUE, with a 3-year certification validity.

Cert Empire’s JN0-352 exam questions are built with the Junos-specific operational precision the real exam demands: OSPF DR/BDR election rules, IS-IS Level 1 versus Level 2 adjacency behavior, BGP route selection attribute sequence, and the specific differentiation of HA mechanisms that determines which question answer is VRRP, which is GRES, and which is NSR.

Exam Snapshot

What the JN0-352 Tests: Major Topic Areas

Layer 2 Switching

VLANs and trunking: Junos EX switch VLAN configuration differs from some vendor conventions in its configuration hierarchy. The exam tests how VLANs are defined in Junos (under vlans stanza), how access ports are assigned to a VLAN (unit 0 with family ethernet-switching, interface mode access, vlan members), and how trunk ports carry multiple VLANs (interface mode trunk, vlan members with VLAN name list or all). Understanding the distinction between family inet (Layer 3 routing) and family ethernet-switching (Layer 2 switching) on an interface is a fundamental Junos exam topic.

Spanning Tree Protocols: The exam tests RSTP (Rapid STP), which is the current standard and default on most Junos platforms. RSTP root bridge election: the switch with the lowest bridge priority wins (default priority 32768). When priorities are equal, the switch with the lowest MAC address wins. A confirmed exam scenario: three switches with bridge priorities of 32768, 8192, and 16384 – the switch with priority 8192 wins the root election purely on priority. MAC address is only used as a tiebreaker when priorities are identical.

RSTP port states and roles: RSTP eliminates most of the delay in classic STP through rapid convergence mechanisms. Key port roles: Root Port (best path to root bridge), Designated Port (forwarding port on each segment), Alternate Port (backup to root port, immediately transitions to forwarding if root port fails – this is the rapid convergence mechanism), Backup Port (backup to designated port on same segment).

OSPF point-to-point interface: A confirmed JN0-352 exam question: enabling the point-to-point parameter on an OSPF interface provides two benefits. First, OSPF adjacency establishes faster because the DR/BDR election process is skipped – on a point-to-point link, there can only be two routers, so DR/BDR election is unnecessary overhead. Second, the Full adjacency state is reached immediately without going through the 2-Way state that occurs during DR/BDR negotiation on broadcast links. Candidates who know that OSPF has DR/BDR elections but do not know when and why to bypass them will miss this question.

OSPF

DR/BDR election: On a broadcast (Ethernet) network, OSPF elects a Designated Router and Backup Designated Router to reduce flooding overhead. Election rules: highest OSPF router priority wins (default 128 in Junos). If priorities are tied, highest Router ID wins. Router ID is determined by: explicitly configured value > highest loopback address IP > highest physical interface IP. A confirmed JN0-352 exhibit question: four routers powered on simultaneously, each with specific router IDs and priorities – which becomes DR, which becomes BDR?

OSPF neighbor states and troubleshooting: Full adjacency is the goal; it means complete LSA database synchronization has occurred. Common stuck states and their causes: Exstart/Exchange (MTU mismatch between neighbors), 2-Way on a point-to-point link (routing protocol configuration mismatch, or the link type is set to broadcast when it should be point-to-point), Init (Hello packets being received but bidirectional communication not confirmed – the local router’s ID is not in the neighbor’s Hello).

LSA types and area types: The JN0-352 tests which LSA types are present in which area types:

• Backbone area: LSA types 1, 2, 3, 4, 5 (all except type 7)
• Stub area: LSA types 1, 2, 3 (no external routes, type 4 and 5 blocked)
• Totally stubby: LSA types 1, 2 only (type 3 blocked, only a default route injected)
• NSSA: LSA types 1, 2, 3, 7 (type 7 is NSSA external, replaces type 5 within the NSSA)

Viewing OSPF metric: A confirmed exam question: how do you view the metric assigned to a route in OSPF? The command show ospf route in Junos displays routes with their costs. The metric for OSPF in Junos is called cost, and it is displayed in the show ospf route output.

IS-IS

IS-IS adjacency requirements: IS-IS uses its own protocol addressing (NSAP/NET addresses), not IP. The exam tests what IS-IS requires for adjacency formation and two common reasons IS-IS adjacencies do not establish:

1. The lo0 interface is not included as an IS-IS interface (required in Junos for IS-IS to function correctly – the loopback provides the System ID).
2. Level 2 routers have mismatched area addresses (Level 1 adjacencies require matching areas; Level 2 adjacencies do not, but misconfigured area values can still cause problems).

The incorrect options (MTU must be at least 1492 bytes – IS-IS has its own minimum MTU consideration but the specific value in the distractors is wrong; IP subnets must be /30 – IS-IS is not IP-dependent and does not require specific subnet masks) are designed to trip candidates who confuse IS-IS with OSPF requirements.

IS-IS levels: Level 1 routers exchange topology within an area. Level 2 routers exchange topology between areas (the IS-IS backbone). Level 1-2 routers participate in both. The exam tests the routing behavior: a Level 1-only router cannot reach destinations in other areas directly; it must use a default route toward the nearest L1-L2 router.

BGP

BGP finite state machine: BGP establishes sessions through a specific state sequence: Idle → Connect → Active → OpenSent → OpenConfirm → Established. A confirmed JN0-352 question asks for the correct BGP state machine order. Candidates who confuse BGP states with OSPF neighbor states will select incorrect answers.

BGP route selection: When multiple paths exist to the same destination, BGP applies a selection process in this order (highest preference wins unless noted):

1. Highest Local Preference (Junos default: 100)
2. Shortest AS-Path length
3. Lowest Origin code (IGP < EGP < Incomplete)
4. Lowest MED (only compared when paths come from the same neighboring AS)
5. Prefer eBGP over iBGP
6. Lowest IGP metric to the BGP next hop
7. Lowest BGP Router ID

A confirmed exam question: evaluating a BGP route where the next hop is not reachable – BGP handles an unreachable next-hop route in two ways: it marks the route as invalid and does not use it for forwarding, and it does not advertise the route to peers.

eBGP vs. iBGP: eBGP runs between routers in different autonomous systems. iBGP runs between routers in the same AS. Key difference: iBGP requires either a full mesh of sessions or the use of route reflectors, because iBGP routers do not re-advertise iBGP-learned routes to other iBGP peers (split horizon rule).

Routing Policy and Firewall Filters

Routing policy structure: A Junos routing policy consists of terms. Each term has a from (match conditions) and a then (actions). From conditions: prefix-list, route-filter, protocol, next-hop, community. Then actions: accept, reject, modify attributes (local-preference, metric, community). The policy is applied at import (routes entering the routing table from a protocol) or export (routes being advertised from the routing table to a protocol).

Firewall filters: Junos firewall filters are stateless, applied per-interface in input or output direction. Filter terms specify match conditions (source/destination address, protocol, port) and actions (accept, discard, reject, count, log). The exam tests the difference between discard (silently drops, no ICMP unreachable sent) and reject (drops and sends ICMP unreachable to sender).

Tunnels

GRE tunnels: GRE (Generic Routing Encapsulation) encapsulates packets for transport across networks that would otherwise not carry them. GRE adds a tunnel header but provides no encryption. Intermediate routers need routes to the tunnel destination but do not need routes to the traffic being tunneled inside the GRE header. This is a confirmed JN0-352 question: what routing information do intermediate devices need? Answer: a route to the tunnel destination address (the GRE endpoint), not a route to the traffic destination inside the tunnel.

IP-in-IP tunnels: Similar to GRE but simpler – encapsulates IPv6 in IPv4 (6in4) or IPv4 in IPv4 for specific traffic transport requirements.

High Availability

VRRP (Virtual Router Redundancy Protocol): Provides gateway IP redundancy for end hosts. Multiple routers share a virtual IP address; the master router responds to ARP requests for that IP. The backup becomes master if the master fails. End hosts do not need to change their default gateway when failover occurs. VRRP solves the “my default gateway failed” problem for client devices.

GRES (Graceful Routing Engine Switchover): Preserves forwarding table (Forwarding Information Base) state on Packet Forwarding Engines during a Routing Engine switchover. Traffic continues flowing without interruption. However, routing protocol neighbors detect the adjacency drop and reconverge (OSPF neighbors go to Down state and re-form adjacency). GRES solves traffic interruption during RE failover but does not prevent protocol reconvergence.

NSR (Nonstop Active Routing): Extends GRES by synchronizing routing protocol state between primary and backup REs in addition to the forwarding table. During a RE switchover, neighbors do not detect any change – the backup RE takes over the routing protocol sessions without a disruption that neighbors can observe. NSR solves complete transparent failover including routing protocol state.

Graceful restart: A routing protocol mechanism (not a hardware HA feature) that allows a restarting router to signal its neighbors that it is restarting. Neighbors continue forwarding based on stale routes for a grace period. The restarting router can then rebuild its routing table using a fresh LSP refresh without causing traffic blackholes. Graceful restart works at the protocol level and does not require dual REs.

5 Study Tips for Juniper JN0-352

• Tip 1: Study VRRP, GRES, and NSR as three distinctly different solutions to three different problems. Know what each preserves (VRRP: gateway IP for hosts; GRES: FIB on PFE; NSR: FIB + routing protocol state). The exam presents HA scenarios and expects you to identify the right mechanism for the stated requirement.
• Tip 2: Practice OSPF DR/BDR election with specific router ID and priority values. The exhibit-based questions show a topology and ask which router becomes DR or BDR – you must apply the election rules in the correct priority order.
• Tip 3: Know the BGP route selection sequence in order. Local preference is compared first. AS-path length is second. You will be given a scenario with two routes and asked which attribute determines the selection – and you must know that local preference is evaluated before AS-path regardless of the magnitude of the AS-path difference.
• Tip 4: Study IS-IS adjacency failure reasons specifically. The lo0 interface requirement and Level 2 area mismatch are confirmed question topics. Practice distinguishing IS-IS requirements from OSPF requirements.
• Tip 5: Practice with Cert Empire’s JN0-352 exam questions updated for the June 8, 2026 exam revision, with Junos-specific operational scenario questions across all JNCIS-ENT topic areas.

Best Study Resources

• Cert Empire JN0-352 exam questions PDF and practice simulator (June 2026 exam update edition).
• Juniper official JN0-352 exam topics (juniper.net – HPE Juniper Networking certification page).
• Juniper Networks JNCIS-ENT Study Guide (official Juniper Press publication).
• Juniper TechLibrary: Junos OS routing protocols and switching documentation.
• Day One books: OSPF for Junos OS, BGP for Junos OS.

Career Opportunities After JN0-352

• Enterprise Network Engineer (Juniper)
• Senior Network Administrator
• Network Architect (Enterprise)
• Juniper Partner Technical Specialist
• Network Operations Center Engineer (Senior)

JNCIS-ENT certified professionals work across financial services, healthcare, education, manufacturing, and government sectors that deploy Juniper enterprise infrastructure. Certified engineers earn between USD 80,000 and USD 120,000 annually.

Why Candidates Choose Cert Empire for JN0-352 Preparation

✔ VRRP vs. GRES vs. NSR differentiation questions. Our questions present HA scenarios requiring candidates to identify which mechanism addresses which requirement: gateway redundancy for hosts (VRRP), FIB preservation during RE switchover (GRES), transparent protocol state preservation (NSR). These are the most frequently missed questions on the real exam.

✔ OSPF DR/BDR election exhibit questions. We present topology scenarios with specific router IDs and priorities and test which router becomes DR and BDR, applying the two-tier election rule (priority first, then router ID as tiebreaker).

✔ BGP route selection sequence questions. Our questions test attribute comparison in the correct order and present scenarios requiring candidates to identify which attribute determines the selection outcome.

✔ June 2026 exam update coverage. Our question bank reflects the June 8, 2026 updated JN0-352 exam.

✔ Practice under real exam conditions with the Cert Empire Exam Simulator. Our JN0-352 simulator runs 65 questions in 90 minutes with topic-level tracking across all JNCIS-ENT domains.

✔ Instant access, 90-day free updates, and 24/7 support. As Juniper updates JN0-352 content, your materials update automatically. Our support team is available around the clock.

✔ Backed by a full money-back guarantee. If our exam questions do not help you pass, we refund your purchase with no conditions.

Readiness Check

1. A network engineer enables the point-to-point parameter on an OSPF interface connecting two routers via a dedicated link. What are the two specific operational benefits of this configuration change, and which OSPF process is eliminated by configuring a link as point-to-point?
2. You are troubleshooting IS-IS in a network where IS-IS adjacencies are not forming between two routers. Both routers are configured as Level 2. After reviewing the configuration, you identify two potential causes. Which two conditions, if present, would prevent IS-IS Level 2 adjacencies from forming, and what would you check to verify each?
3. A dual-RE Juniper router experiences a Routing Engine switchover. After the switchover, the network operations team observes that OSPF neighbors re-formed adjacency and reconverged routing tables, but no traffic was dropped during the switchover itself. Which high availability mechanism was configured on this router, and what additional mechanism would have prevented the OSPF neighbors from detecting the RE switchover?
4. A BGP engineer reviews two paths to the same destination prefix. Path A has Local Preference 200 and AS-path length of 3. Path B has Local Preference 100 and AS-path length of 1. Which path does BGP select, and which attribute determines the outcome without evaluating subsequent attributes in the selection process?
5. An RSTP network has three switches: Switch A with bridge priority 32768, Switch B with bridge priority 8192, and Switch C with bridge priority 16384. All switches power on simultaneously. Which switch becomes the root bridge, what attribute determined this outcome, and under what specific condition would MAC address be used as the tiebreaker instead?

FAQ’s

What is the Juniper JN0-352 JNCIS-ENT exam?

The JN0-352 is the Enterprise Routing and Switching, Specialist (JNCIS-ENT) exam. It validates intermediate knowledge of enterprise network routing and switching using Junos OS, covering Layer 2 switching, OSPF, IS-IS, BGP, routing policy, tunnels, and high availability. The exam was updated June 8, 2026.

What is the difference between NSR and GRES on Juniper platforms?

GRES (Graceful Routing Engine Switchover) preserves the forwarding table (FIB) on Packet Forwarding Engines during an RE switchover, keeping traffic flowing. However, routing protocol neighbors detect the adjacency change and reconverge. NSR (Nonstop Active Routing) additionally synchronizes routing protocol state between primary and backup REs, so neighbors do not detect the switchover at all – no reconvergence occurs.

What are the BGP route selection attributes and their order?

In order of preference: Local Preference (highest wins) → AS-Path length (shortest wins) → Origin code (IGP < EGP < Incomplete) → MED (lowest wins) → Prefer eBGP over iBGP → Lowest IGP metric to next hop → Lowest BGP Router ID.

What is the OSPF point-to-point interface parameter used for?

Configuring point-to-point on an OSPF interface eliminates the DR/BDR election process on that interface. This speeds up OSPF adjacency formation (no waiting for DR/BDR election) and is appropriate for dedicated two-router links where DR/BDR election adds unnecessary overhead.

Related Certifications Worth Exploring

JNCIS-ENT professionals advancing to the professional level will find our Juniper JNCIP-ENT (JN0-649) exam questions page covers the advanced enterprise routing and switching content that builds directly on JNCIS-ENT. For those in the Juniper security track alongside enterprise routing, our Juniper JNCIS-SEC (JN0-334) exam questions page covers the security specialist certification that pairs with JNCIS-ENT for enterprise network security roles.