Juniper JN0-336 - Security, Specialist (JNCIS-SEC)

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 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 answer is C. device policy rules. In Junos Space Security Director, policy scope matters. A rule intended for one specific SRX Series device must be placed in a device policy, because Juniper defines a device policy as a firewall policy created per device and used when you want to push a unique firewall policy configuration per device. Security Director also distinguishes this from group policies, which are shared with multiple devices, and from all-devices policy rules, which are global in scope rather than device-specific.

Option A is wrong because all-devices prerules are global rules evaluated before device-specific rules; they are not intended for a unique single-device exception. Option B is wrong because group policy prerules apply to devices within a group, not to one individually targeted SRX firewall. Option D is wrong because all-devices postrules are still globally scoped, even though they occur later in policy order. The clean Security Director design is to use device policy rules when the policy must apply only to one SRX device. Reference topics: Security Director, firewall policy hierarchy, device policy, group policy, all-devices prerules/postrules.

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 answers are A and C. In SSL forward proxy, the SRX sits between internal clients and external SSL/TLS servers. Juniper’s SSL proxy configuration documentation shows that a forward proxy profile is created when root-ca is configured and server-certificate is not configured. This root CA is used by the SRX to generate substitute certificates for intercepted SSL sessions, so internal clients must trust the CA used by the firewall. Juniper’s procedure specifically includes generating or loading a local certificate and applying it as the root-ca in the SSL proxy profile.

Option C is also correct because forward proxy terminates the client-side SSL session and establishes a separate SSL session toward the destination server. Juniper states that the SSL proxy acts as an SSL server to the client and establishes a new SSL session to the server; from the server’s perspective, the SRX is the SSL client. Option B is wrong because forward proxy intercepts the server certificate and creates a substitute certificate; forwarding the actual server certificate unchanged is associated with reverse proxy behavior. Option D is wrong because Encrypted Traffic Insights is not the required forward-proxy mechanism here. Reference topics: SSL Proxy, SSL forward proxy, root CA, client protection, certificate interception.

The correct answers are A and D. Preparing Active Directory for JIMS requires creating limited-permission service accounts and assigning those accounts to the required Active Directory groups. Juniper’s JIMS deployment guidance states that you must create service accounts so JIMS can read from the defined directory services and identity producers; if PC probing is used, a service account is also required for that function. The same JIMS documentation includes a section named Configure Limited-Permission User Accounts, followed by Add Limited Permission User Accounts to Active Directory Groups.

Option A is correct because the JIMS preparation workflow commonly uses limited-permission accounts for event log access and PC probe access. Juniper identifies accounts such as JIMS-EventLogRemoteAccess and JIMS-PC-Probe in the Active Directory group-membership procedure. Option D is correct because those limited accounts must be added to the proper AD groups, including Event Log Readers and the groups required for remote management or PC probe operation.

Option B is wrong because the tested preparation requirement is not three limited-access accounts. Option C is wrong because JIMS should not be prepared by adding a broad full-access account; the course objective is least-privilege identity collection. Reference topics: JIMS, Active Directory preparation, limited-permission service accounts, Event Log Readers, PC probe account.

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 A. It supports a maximum of two domains. Juniper’s Active Directory identity-source configuration guidance states that an SRX Series Firewall using the integrated user firewall/Active Directory identity source can be configured for a maximum of two domains. That is the exact limit relevant to this question. The same Juniper configuration page separately states that a maximum of 10 domain controllers can be configured, which directly eliminates option C because the supported figure is not 20 Active Directory servers per domain.

Option B is wrong because Active Directory identity source is not presented as a logical-systems feature in the JNCIS-SEC identity-aware firewall context. Option D is wrong because the primary Active Directory mechanism reads Windows domain controller event logs and uses WMI/DCOM plus LDAP to build IP-to-user and group mappings. Juniper describes the SRX as reading and monitoring the Windows event log on the domain controller, then using LDAP to obtain user/group information. Non-domain or non-Windows cases typically require alternate authentication behavior such as captive portal, not native Active Directory event-log tracking.

Reference topics: Identity-Aware Security Policies, Active Directory identity source, integrated user firewall, domain limits, domain controllers, WMIC, LDAP mapping.