JN0-336 Security, Specialist (JNCIS-SEC) Questions and Answers

The correct answers are A and B. In SRX chassis clustering, the fabric link, represented by fab interfaces, is the data-plane connection between the two cluster nodes. Juniper describes the fabric as the back-to-back data connection used when traffic on one node must be processed on the other node or must exit through an interface on the other node; session-state information also passes over the fabric. This is especially visible in active/active clustering, where ingress and egress interfaces can reside on different nodes and transit traffic must cross the fabric link.

Option B is also correct because the fabric link still exists in active/passive clustering for cluster data-plane synchronization and inter-node state handling, even though active/passive designs minimize fabric transit traffic because only one node normally forwards traffic at a time. Juniper specifically states that active/passive mode minimizes traffic over the fabric link, not that the fabric link is unused.

Options C and D are not the intended answers. The cluster is identified by a configured cluster ID, and each chassis is identified by a node ID, but the fabric interface names themselves are not where the cluster ID is reflected. Reference topics: HA Clustering, fabric link, active/active clustering, active/passive clustering, session synchronization, inter-node traffic.

The correct answers are A and D. A mobile command center using a 5G ISP behind CGNAT is operating behind dynamic address translation. For IPsec to work reliably through NAT, the SRX must support NAT Traversal, which encapsulates IKE and ESP traffic in UDP/4500 after NAT is detected. Juniper states that NAT-T is used when NAT devices exist in the datapath and that NAT keepalives are required because NAT devices age out UDP translations. Juniper’s Security Director VPN workflow also specifically says to enable NAT-T when the dynamic endpoint is behind a NAT device.

DPD is also required because mobile and carrier-grade NAT connections can disappear, roam, or become stale without a clean tunnel teardown. Juniper defines Dead Peer Detection as the method used by IPsec peers to verify whether the remote peer is still present and responsive by sending encrypted IKE notification payloads and waiting for acknowledgements. Option B is not the best answer because IKEv1 aggressive mode is weaker and does not provide identity protection; Juniper also notes that aggressive mode applies only to IKEv1. Option C is invalid because IKEv2 aggressive mode does not exist. Reference topics: IPsec VPN, NAT-T, CGNAT, dynamic endpoints, DPD, IKE peer availability.

The correct answers are B and C . A redundant Ethernet interface, or reth , is a logical interface used in an SRX chassis cluster to provide interface redundancy across node0 and node1. Juniper states that a reth interface must include matching physical Ethernet interface types and speeds on both cluster nodes. In practical terms, you cannot build one reth bundle by mixing Fast Ethernet with Gigabit Ethernet, or by mixing different speed members inside the same redundant Ethernet interface. Juniper’s chassis cluster documentation explicitly states that mixed Ethernet interface types or speeds within a single reth interface are not supported.

Option B is correct because all member interfaces must use the same media/interface type, such as Fast Ethernet with Fast Ethernet or Gigabit Ethernet with Gigabit Ethernet. Option C is correct because the child interfaces must also operate at the same speed. Option A is wrong because speed mismatch is unsupported and can prevent a child link from joining the reth bundle. Option D is wrong because different media types are not valid within the same reth interface. Reference topics: HA Clustering, redundant Ethernet interfaces, reth child interfaces, interface type and speed requirements.

The correct answers are C and D. Juniper Secure Connect is Juniper’s remote-access VPN client for SRX Series Firewalls. Juniper describes it as a flexible SSL VPN and IPsec application that gives remote workers secure access to corporate and cloud-protected resources. That directly supports option D, because SSL VPN provides a connection method that is useful when traditional IPsec ports are restricted or blocked. Juniper’s Secure Connect guide also states that enabling SSL VPN gives the client flexibility in connecting to SRX Series Firewalls and that SSL VPN is enabled by default.

Option C is also correct because Juniper Secure Connect supports external authentication, allowing users to authenticate with enterprise identity systems rather than relying only on local firewall credentials. Juniper’s external authentication procedure notes that this method lets users use the same username and password as their domain login and is recommended for authenticating users.

Option A is not the best answer because having a client application is not the specific connection/authentication flexibility being tested. Option B is wrong because Kerberos is not the stated Secure Connect authentication method in this context. Reference topics: Juniper Secure Connect, remote-access VPN, SSL VPN, IPsec, external authentication.

The correct answers are B, D, and E. Security Director device onboarding depends on management reachability and valid administrative access. Juniper’s device discovery documentation states that Junos Space discovers network devices using SSH, with optional ping and SNMP, and connects to the physical device to retrieve running configuration and status information. It also explains that device authentication uses administrator login credentials, SSH credentials, SNMP settings, or keys depending on the discovery method.

Option E is required because Security Director must target a reachable management IP address or hostname. Juniper’s discovery-profile workflow explicitly uses the target IP address, hostname, IP range, or subnet to locate devices. Option D is required because invalid username/password or insufficient privileges prevent discovery and management; Juniper’s device-management guidance identifies credentials as required input for discovering devices. Option B is required because onboarding uses SSH, so the correct SSH service and port must be reachable. Juniper’s device access procedure explicitly includes a Port field for the SSH connection.

Option A is wrong because chassis serial number is not the normal troubleshooting field for Security Director discovery. Option C is wrong because active security policies do not determine whether Security Director can initially discover and onboard the device. Reference topics: Security Director, device discovery, SSH access, management IP reachability, authentication credentials.

The correct answers are A and B. In Security Director-managed environments, Security Director can download the signature database and then install the active signature database update on selected managed devices. Juniper’s Security Director workflow states that after the signature database is downloaded, you install the active database, select the target devices, and Security Director sends the full or incremental signature database update to those devices. That confirms that Security Director stores and manages the signature database package centrally for deployment.

Option B is also correct because the SRX Series device must have the application signature database installed locally for AppID/AppSecure features such as AppFW, AppTrack, AppQoS, and IDP application matching. Juniper’s AppID documentation states that the application package is installed in the application signature database on the device, and that AppID signature updates enable AppSecure features on the SRX.

Option C is wrong because Juniper provides and maintains the predefined AppID database through Juniper’s security download infrastructure, not a third-party host. Juniper explicitly describes the predefined application identification database as provided by Juniper Networks and updated through a subscription service. Option D is wrong because a local storage server can be used only as part of an offline/manual update workflow; it is not where the AppID database normally resides. Reference topics: Security Director, AppID database, application signatures, SRX AppSecure services, signature database installation.

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 B and C. Juniper ATP Cloud improves security by delivering cloud-based threat detection, malware analysis, and enforcement integration with SRX Series Firewalls. Juniper describes ATP Cloud as using shared cloud intelligence so customers benefit from new threat intelligence in near real time. It also provides zero-day threat protection, machine-learning-based malware detection, inline malware blocking, and policy actions that can stop malware, quarantine infected systems, prevent data exfiltration, and disrupt lateral movement.

Option C is also correct because Juniper ATP Cloud uses dynamic analysis, commonly called sandboxing. In this process, a suspicious file is executed in a secure environment while tools monitor its activity. Juniper further explains that ATP Cloud uses deception techniques to make the sandbox appear like a real user environment, including simulated mouse movement, keystrokes, common software packages, realistic network access, stored credentials, and vulnerable OS areas. This encourages evasive malware to execute and reveal malicious behavior.

Option A is weaker and not the best answer because logging alone is not the key ATP Cloud security-improvement mechanism being tested. Option D is wrong because ATP Cloud is a threat-prevention service, not a performance-acceleration technology. Reference topics: ATP Cloud, malware analysis, dynamic sandboxing, machine learning, threat intelligence, inline malware blocking.

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. 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 answer is B. ip-notify. When administrators want visibility without enforcement impact, ip-notify is the correct IP action. Juniper Security Director documentation defines IP Notify as an IP action that does not take any action against future traffic but logs the event. That is exactly the requirement in the question: traffic matching the IDP condition must not be blocked, closed, or rate-limited until administrators have reviewed the events and decided whether enforcement is appropriate.

Option A, ip-block, is wrong because it blocks future packets matching the IP action rule. That would immediately impact traffic. Option C, ip-connection-rate-limit, is wrong because it limits the connection rate and therefore changes traffic behavior before administrators complete evaluation. Option D, ip-close, is also wrong because it closes matching future sessions by sending reset packets to the client and server, which is disruptive. In a safe evaluation or tuning phase, the proper approach is to log and observe first, then move to stronger actions such as block, close, or rate-limit only after the detected condition has been validated. Reference topics: IDP IP actions, ip-notify, event logging, non-disruptive evaluation mode, IDP policy tuning.

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 B and D. A terminal rule is specifically designed to stop further rule evaluation. Juniper states that the IDP rule-matching algorithm normally checks traffic against all matching rules in the rulebase, but when a terminal rule matches the source, destination, zones, and application, IDP does not continue to check subsequent rules for that same traffic. Juniper also warns that traffic matching a terminal rule is not compared to later rules even if it does not match the attack object inside that terminal rule.

Option D is also correct because the Ignore Connection action stops scanning traffic for the rest of the connection if an attack match is found. Juniper defines Ignore Connection as disabling the rulebase for that specific connection after a match. Option A is wrong because a close action closes the connection by sending reset behavior, but it is not the rule-processing control mechanism being tested. Option C is a trap: the exempt rulebase is used to suppress known false positives after an IPS rule match, but the two direct mechanisms that end IDP rule processing are terminal rule matching and ignore connection. Reference topics: IDP rulebases, terminal rules, Ignore Connection action, rule-matching algorithm, false-positive exemption.

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 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 A, C, and E. Junos Space Security Director supports policy hierarchy and policy management at device, group, and global/all-devices levels. A device policy is created for a specific device and is used when a unique firewall policy must be pushed to one SRX Series Firewall. A group policy is shared across multiple devices and is used when the same policy configuration must be applied consistently to a set of managed firewalls. Juniper’s Security Director documentation explicitly describes device policy and group policy behavior, including the fact that device-specific policies are evaluated within the broader policy-ordering model.

The third correct policy type is global, often represented in Security Director workflows as all-devices/global policy behavior. Juniper Security Director product material describes granular control over global, group, and device-level firewall policies, which maps directly to the options in this question. Option B, local, is not the Security Director policy type being tested; local configuration may exist on an SRX, but it is not one of the Security Director policy hierarchy types listed here. Option D, universal, is also not a Junos Space Security Director policy type. Reference topics: Security Director, global policy, group policy, device policy, firewall policy hierarchy, centralized SRX policy management.

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.