JN0-336 Juniper Security, Specialist (JNCIS-SEC) Free Practice Exam Questions (2026 Updated)

The correct answer is D. You have too many domain controllers. The exhibit shows 15 Active Directory domain controllers. Juniper’s integrated Active Directory identity-source configuration for SRX identity-aware firewall supports a limited number of domain controllers; Juniper documentation states that an SRX Series device can configure a maximum of 10 domain controllers for Active Directory identity-source integration. Because this environment has 15 domain controllers, the direct Active Directory identity-source method exceeds the supported scale and JIMS must be used instead.

Option A is wrong because SRX devices can use Active Directory directly as an identity source; JIMS is not the only possible method. Option B is wrong because 1,500 users does not exceed the relevant identity-source scale shown here; Juniper documentation also notes probe functionality support well above this number. Option C is wrong because the issue being tested is not the Windows Server version. JIMS is designed for larger identity-aware deployments and can centralize identity collection from Active Directory, domain controllers, Exchange servers, and syslog sources, then provide identity mappings to SRX firewalls. Juniper’s JIMS datasheet shows much higher scale, including up to 100 active directories, 25 domains, and 500,000 user entries. Reference topics: Identity-Aware Security Policies, Active Directory identity source limits, JIMS scalability, domain controller scale limitations.

The correct answer is D. exempt. In Junos IDP, the exempt rulebase is specifically used to prevent selected traffic from triggering known false-positive detections. Juniper’s IDP documentation explains that exempt rules can be configured when an IDP policy generates false positives for a particular attack object, source, destination, or traffic pattern. The exempt rulebase lets the administrator exclude matching traffic from attack detection while still allowing the rest of the IDP policy to inspect other traffic normally.

Option A, IPS, is wrong because the IPS rulebase is the main inspection rulebase used to detect and act on attacks. It is where attack objects and actions are commonly applied, but it is not the rulebase designed to eliminate false positives. Option B, monitor, is not the correct false-positive elimination mechanism. Monitoring can help observe behavior, but it does not exempt traffic from matching an attack object. Option C, signature, is wrong because signatures are attack-detection patterns, not a rulebase type used to suppress false positives. The operational correction for noisy or irrelevant matches is to create an exempt rule for the specific trusted source, destination, or attack object. Reference topics: IDP rulebases, exempt rulebase, false-positive tuning, attack objects, IPS inspection.

The correct answers are C and D. The exhibit shows ESP encrypted bytes = 0, ESP decrypted bytes = 0, encrypted packets = 0, and decrypted packets = 0. That means no traffic is successfully passing through the IPsec tunnel. Juniper’s show security ipsec statistics command displays ESP encrypted/decrypted packet and byte counters, so zero values on these counters indicate that the tunnel is not successfully carrying protected ESP traffic.

Option C is also correct because the output shows ESP authentication failures and ESP decryption failures. Since ESP is the IPsec protocol responsible for encrypted payload handling, failures in ESP authentication/decryption point to an ESP/IPsec Phase 2 mismatch or incorrect configuration, such as mismatched authentication algorithm, encryption algorithm, keys, proposal parameters, or incompatible negotiated SA settings. Juniper’s IPsec overview explains that Phase 2 negotiates the IPsec SA used to authenticate traffic flowing through the tunnel, so ESP-related failures belong to the IPsec/ESP configuration path rather than AH.

Option A is wrong because the AH counters and AH authentication failures are zero; the evidence is not pointing to AH. Option B is unsupported because the output does not show peer reboot behavior. Reference topics: IPsec VPN, ESP statistics, Phase 2/IPsec SA negotiation, ESP authentication failures, ESP decryption failures.

The correct answer is A. by granting access based on user roles or identities. Juniper identity-aware firewall moves enforcement beyond simple IP-address-based policy by associating traffic with authenticated users, groups, devices, and roles. Juniper states that identity parameters can be used to configure security policies so that policies provide the appropriate level of access to authenticated users. It further explains that identity helps secure access to resources based on username, roles, and groups, and that firewalls can create and enforce rules based on user identity rather than only an IP address.

This directly supports compliance because regulated environments usually require least-privilege access, auditable user-based control, and role-based authorization. Option B is wrong because identity-aware security might simplify policy operations in some cases, but network architecture simplification is not its compliance function. Option C is wrong because capacity expansion has no direct relationship to identity-based regulatory enforcement. Option D is too vague and not the mechanism being tested; confidentiality is a security goal, but identity-aware firewall enforces access decisions by mapping traffic to users and groups. Reference topics: Identity-Aware Security Policies, user identity, role-based access control, group-based policy enforcement, authentication table.

The correct answers are A and D. In IKEv1-based IPsec VPNs, there are two distinct negotiation phases. IKEv1 Phase 1 establishes the secure and authenticated IKE channel between peers. That means the IKE SA is built during Phase 1. Juniper describes Phase 1 as the negotiation of proposals for how to authenticate and secure the channel, including encryption algorithms, authentication algorithms, Diffie-Hellman group, and authentication method.

IKEv1 Phase 2 then uses that secure channel to negotiate the IPsec SAs that protect actual user traffic through the VPN. Juniper states that Phase 2 negotiates security associations to secure the data traversing the IPsec tunnel, and that the Phase 2 proposal includes the security protocol, such as ESP or AH, plus the selected encryption and authentication algorithms. Option B is wrong because IKEv1 SAs are not established in Phase 2; Phase 2 creates IPsec SAs. Option C is wrong because Phase 1 does not create the data-plane IPsec SA; it creates the secure IKE control channel used for Phase 2 negotiation. Reference topics: IPsec VPN, IKEv1 Phase 1, IKE SA, IKEv1 Phase 2, IPsec SA, ESP/AH proposals.

The correct answers are A and B. In SRX chassis clustering, the fab interface is the fabric data-plane link between cluster nodes. Juniper explains that data-plane software synchronizes session state using runtime objects, or RTOs, across the fabric data link, and this fabric link also supports forwarding traffic between nodes when ingress and egress processing occur on different chassis members.

swfab is also a chassis-cluster data-plane-related interface used for Layer 2 switching fabric functionality. Juniper’s Ethernet switching on chassis cluster documentation describes swfab0 and swfab1 as pseudointerfaces created for Layer 2 fabric functionality, enabling switching across the nodes. Option C, fxp1, is wrong because fxp1 is the control link interface used for cluster control-plane communication, heartbeats, and synchronization signaling, not a data-plane fabric interface. Option D, fxp0, is wrong because fxp0 is the out-of-band management interface. The clean separation is: fxp0 = management, fxp1 = control link, fab = routed/data fabric, and swfab = Layer 2 switching fabric. Reference topics: HA Clustering, fab interfaces, swfab interfaces, control link, management interface, data-plane synchronization.

The correct answers are B and C. Juniper IDP uses attack objects as match conditions inside IDP policy rules. Juniper states that IDP attack objects represent known and unknown attacks and that the predefined attack object database is periodically updated by Juniper Networks. The main IDP attack object types include signature attack objects, protocol anomaly attack objects, and compound attack objects.

Option C is correct because signature attack objects detect known attacks using stateful attack signatures. Juniper defines a signature as a pattern that exists within a specific section of an attack and includes protocol, service, direction, flow, and context information to reduce false positives.

Option B is correct because protocol anomaly attack objects detect abnormal protocol behavior. Juniper explains that protocol anomaly objects identify unusual or ambiguous traffic that violates protocol specifications, RFCs, or common RFC extensions.

Option A is wrong because “statistic-based” is not one of the IDP attack object database types being tested here. Option D is wrong because “vector-based” is not a Juniper IDP attack object type. Reference topics: IDP, attack object database, signature-based attack objects, protocol anomaly attack objects, predefined attack objects.

The correct answers are A and D. Juniper ATP Cloud reduces inspection delay in two practical ways: trusted allowlists and cache lookup. An allowlist contains known trusted IP addresses, hashes, email addresses, and URLs; Juniper states that content downloaded from locations on the allowlist does not have to be inspected for malware. That eliminates unnecessary cloud-analysis cycles for known trusted sources or objects.

Option D is also correct because ATP Cloud performs a real-time cache lookup before deeper analysis. Juniper explains that when a file is uploaded, ATP Cloud first checks whether the file has been analyzed before; if it has, the stored verdict is returned to the SRX Series Firewall and there is no need to re-analyze the file. This directly reduces inspection delay and enables faster enforcement. Option B is wrong because ATP Cloud does not rely on a single antivirus engine; it uses a pipeline that can include cache lookup, antivirus, static analysis, dynamic analysis, and machine learning. Option C is wrong because inspection bypass is not delegated to end users. Reference topics: ATP Cloud, allowlists, file inspection workflow, cache lookup, malware analysis pipeline.

The correct answers are B and C. In an SRX chassis cluster, the fabric connection is represented by two logical fabric interfaces: fab0 and fab1. Juniper configuration examples show fab0 assigned to the node0-side fabric member interface and fab1 assigned to the node1-side fabric member interface; for example, Juniper shows fab0 using a node0 interface such as ge-0/0/1 and fab1 using a node1 interface such as ge-7/0/1. That eliminates option A, because fab0 and fab1 are not both independently located on both nodes; they represent the two node sides of the cluster fabric link.

Option C is also correct. Juniper states that only the same type of interfaces can be configured as fabric children, and for dual fabric links both child interface types should match, such as Gigabit Ethernet with Gigabit Ethernet or 10-Gigabit Ethernet with 10-Gigabit Ethernet. Option D is therefore wrong because mixed media types are not supported for the redundant fabric child interfaces. Reference topics: HA Clustering, chassis cluster fabric interfaces, fab0/fab1, redundant fabric links, fabric child interface requirements.

The correct answers are A and B. The exhibit shows show chassis cluster statistics. Under Control link statistics, Control link 0 has heartbeat packets sent and received, with heartbeat packet errors: 0. That is the clearest indication that the control link is operating normally. Juniper describes chassis-cluster control-plane verification as checking control-link heartbeat packets sent and received, along with heartbeat errors. If both send and receive counters are incrementing and errors are zero, the control link is functioning.

Option A is also correct because under Fabric link statistics, Child link 0 shows probes sent and probes received. Juniper uses fabric-link probe counters to verify fabric-link operation; nonzero sent and received probe counters indicate that the link is participating in fabric monitoring. Option C is not the safest conclusion from this exhibit alone. Child link 1 shows zero probes sent and received, but the output does not prove that a second fabric child link is configured and failing; it could simply be unused or not configured in this deployment. Option D is directly contradicted by the healthy heartbeat counters. Reference topics: HA Clustering, chassis cluster statistics, control-link heartbeat, fabric-link probes, cluster health verification.

The correct answers are A and C. In an SRX chassis cluster, redundant Ethernet interfaces are configured as reth interfaces. Juniper defines a reth interface as a pseudointerface that includes at least one physical interface from each node in the cluster. Therefore, assigning a physical interface from node0 and a physical interface from node1 to the same reth interface is mandatory for redundant Ethernet operation. Juniper also states that before configuring chassis cluster redundant Ethernet interfaces, you must set the number of redundant Ethernet interfaces.

Option C maps to the required reth-count configuration under the chassis cluster hierarchy. Without defining the number of reth interfaces, Junos does not know how many redundant Ethernet pseudointerfaces are available for the cluster configuration. Option B is wrong because setting a retry interval is not a required step for creating a reth interface or redundancy group. Option D is wrong because heartbeat behavior belongs to cluster control-link monitoring and chassis-cluster node health, not to the required configuration steps for Ethernet reth membership. The required design steps are: define reth capacity, create/configure the reth interface, assign child physical links from both nodes, and associate the reth with the proper redundancy group. Reference topics: HA Clustering, redundant Ethernet interfaces, reth-count, reth child interfaces, redundancy groups.

The correct answers are A, D, and E. In IPsec VPN terminology, DES, 3DES, and AES are encryption algorithms used to provide confidentiality for protected IP traffic. Juniper’s IPsec material identifies AES, DES, and Triple DES/3DES as IPsec encryption standards, while separating them from authentication hash algorithms such as MD5, SHA-1, and SHA-2. This distinction matters heavily in JNCIS-SEC because IPsec proposals contain different cryptographic functions: encryption protects packet confidentiality, while authentication/hash algorithms validate integrity and origin.

Option B, SHA-1, is incorrect because SHA-1 is a hashing/authentication algorithm, not an encryption algorithm. It produces a message digest used for integrity checking and authentication, commonly as an HMAC variant. Option C, MD5, is also incorrect for the same reason: MD5 is a message-digest algorithm used for authentication/integrity, not for encrypting payload data. AES is the modern preferred encryption family because it is cryptographically stronger than DES and 3DES at comparable key strengths, while DES and 3DES remain historically recognized IPsec encryption algorithms. Reference topics: IPsec VPN, IPsec proposals, encryption algorithms, authentication algorithms, DES, 3DES, AES, SHA, and MD5.

The correct answers are A, C, and E. During Security Director device discovery, Junos Space first finds and connects to the managed device, then synchronizes the device inventory and configuration into the Junos Space database. Juniper’s Security Director documentation states that discovery uses a discovery profile containing target information, authentication credentials, probes, and SSH fingerprints. During discovery, Junos Space connects to the physical device and retrieves the running configuration and status information. It also states that Junos Space uses SSH, with optional ping and SNMP, to discover network devices.

Option B is wrong because device discovery is not a reboot operation. Rebooting would be disruptive and is not part of onboarding a managed SRX into Security Director. Option D is wrong because discovery does not automatically inject a local superuser into the SRX configuration. Security Director authenticates using credentials supplied in the discovery profile; it does not create privileged local accounts as a discovery action. The tested workflow is management-plane discovery: connect, authenticate, retrieve inventory/status, and import configuration state. Reference topics: Security Director, device discovery, discovery profiles, SSH, running configuration import, device status synchronization.

The correct answer is A. It uses AppID services. Juniper SSL proxy does not rely only on TCP/443 or a static destination-port assumption. It uses Application Identification services to dynamically determine whether the session is SSL/TLS encrypted. Juniper states directly that SSL proxy uses application identification services to detect whether a session is SSL encrypted, and SSL proxy is allowed only when the session is identified as encrypted. If the application system cache marks the session as Encrypted=Yes, SSL proxy can transition into proxy processing; if the session is marked Encrypted=No, SSL proxy ignores it.

Option B is wrong because packet length does not reliably identify SSL/TLS encryption. Option C is a common trap: many SSL/TLS sessions use port 443, but SSL/TLS can run on nonstandard ports, and non-SSL applications can also use port 443. Junos uses AppID to avoid that weak assumption. Option D is wrong because a CA is used to sign or validate certificates during SSL forward or reverse proxy operations; it is not the mechanism used to detect whether a session is encrypted. Reference topics: SSL Proxy, AppID, encrypted session detection, application system cache, SSL/TLS inspection.

The correct answer is B. Add custom-attack Custom-FTP-Attack to the attacks section and change the action to drop-packet. In the exhibit, the IDP rule is built under rulebase-ips with a match block and a then block. Attack objects belong inside the match attacks hierarchy because they define what malicious pattern the IDP rule is trying to detect. Juniper’s IDP documentation states that attack objects are specified in rules to identify malicious activity and that the rule’s attack objects/groups are the attacks the device matches in monitored traffic.

The enforcement behavior belongs in the then action hierarchy. The current rule uses close-client; to meet the requirement, it must be changed to drop-packet. Juniper defines Drop Packet as an IDP action that drops a matching packet before it reaches its destination without closing the connection. Option A keeps the wrong action. Option C is structurally wrong because a custom attack object is not configured under the action section. Option D is also wrong because the notification section controls logging/alert behavior, not attack matching. Reference topics: IDP rulebase, custom attack objects, match attacks hierarchy, IDP actions, drop-packet behavior.

The correct answer is B. ESP. In IPsec, the security protocol responsible for encrypting protected traffic is Encapsulating Security Payload (ESP). Juniper defines ESP as the IPsec protocol used for encrypting the IP packet and authenticating its contents. In practical SRX VPN design, ESP is the normal protocol selected when confidentiality is required because it can provide encryption, packet integrity, authentication, and anti-replay protection depending on the configured IPsec proposal.

Option A, SHA-1, is incorrect because SHA-1 is an authentication/hash algorithm, not an IPsec security protocol and not a payload encryption mechanism. Option C, AH, is incorrect because Authentication Header validates packet source and integrity but does not encrypt payload data. AH is therefore unsuitable when the requirement explicitly says payload data must be encrypted. Option D, PFS, is incorrect because Perfect Forward Secrecy is a key-exchange property used during Phase 2 rekeying; it strengthens key independence but does not itself encrypt packets. In Junos IPsec configuration logic, the security protocol decision is between ESP and AH, and encryption requires ESP. Reference topics: IPsec VPN, ESP, AH, IPsec security protocols, payload confidentiality, IPsec proposal design.

The correct answers are A and B. In an SRX chassis cluster, the cluster ID identifies the chassis cluster, and valid operational cluster IDs are nonzero values. Juniper’s chassis cluster command documentation states that the system uses the chassis cluster ID and node ID to apply the correct node-specific configuration, and the command writes the chassis cluster ID and node ID to EPROM. When the cluster ID is set to 0, clustering is disabled; therefore, the HA cluster configuration is effectively ignored because the device is no longer operating as a chassis-cluster member.

Option B is also correct because Juniper states that chassis cluster ID and node ID changes take effect only after the system is rebooted. That is why the operational command format includes the reboot behavior when setting cluster-id and node. Option C is wrong because node ID 0 is valid; it identifies node0 in the two-node cluster. Option D is wrong because SRX chassis clusters use node IDs 0 and 1 only; the 1–255 range applies to cluster IDs, not node IDs. Reference topics: HA Clustering, cluster ID, node ID, EPROM, chassis cluster enablement, node-specific configuration.

The correct answer is D. maintaining a centralized authentication table. Juniper Identity Management Service, or JIMS, is used with SRX Series Firewalls to collect user-identity information from identity sources such as Microsoft Active Directory, domain controllers, and Exchange servers, then provide that identity data to SRX enforcement points. Juniper describes JIMS as storing IP address, username, and group-relationship information in its cache and generating authentication entries used for user-based or group-based access control on SRX firewalls. Juniper’s Identity-Aware Firewall documentation also states that the authentication table contains the IP address, username, and group mapping information used as the authentication source.

Option A is wrong because JIMS is not an email-encryption service. Option B is wrong because malicious-code logging belongs to security inspection features such as antivirus, IDP, or ATP workflows, not JIMS. Option C is wrong because network data encryption is handled by technologies such as IPsec VPN or SSL/TLS, not identity management. JIMS exists to centralize identity-to-IP mapping so identity-aware security policies can match users and groups instead of relying only on source IP addresses. Reference topics: Identity-Aware Security Policies, JIMS, authentication table, user-to-IP mapping, group-based policy enforcement.

The correct answers are B and D. IKE Phase 2 negotiates the IPsec security associations used to protect actual user data through the VPN tunnel. Juniper explains that after Phase 1 establishes a secure authenticated channel, Phase 2 negotiates SAs for the data transmitted through the IPsec tunnel. A Phase 2 proposal includes the IPsec security protocol, which is either ESP or AH, along with selected encryption and authentication algorithms. In the wording of this question, that maps to the tunnel/security protocol property.

Option D, Perfect Forward Secrecy, is also correct because Phase 2 proposals can specify a Diffie-Hellman group when PFS is desired. PFS forces a new DH key exchange for Phase 2 keys so that compromise of earlier keying material does not expose later IPsec encryption keys. Option A is wrong because routing protocols are not negotiated by IKE Phase 2; routing is handled separately over or toward the tunnel interface. Option C is wrong because aggressive mode is an IKEv1 Phase 1 exchange mode, not a Phase 2 property. Juniper specifically states that Phase 2 always uses quick mode in IKEv1. Reference topics: IKE Phase 2, IPsec SA negotiation, ESP/AH, Perfect Forward Secrecy, quick mode.