Pass the Juniper JNCIS-SEC JN0-336 Questions and answers with CertsForce

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. by using AppID results. Junos SSL proxy does not identify SSL/TLS sessions by assuming that encrypted traffic always uses TCP/443. That would be technically weak because SSL/TLS can run on nonstandard ports, and non-SSL applications can also use common HTTPS ports. Juniper’s SSL proxy documentation explains that SSL proxy works with application security services and that AppID is used in the encrypted-traffic inspection workflow. In earlier wording from Juniper AppSecure material, SSL proxy uses application identification services to determine whether a session is SSL encrypted; in current Junos documentation, SSL proxy and AppID are tightly linked so encrypted sessions can be identified, decrypted, inspected, and then re-encrypted for enforcement.

Option A is wrong because the URL is inside the HTTP payload, and in HTTPS much of the meaningful HTTP content is encrypted before SSL proxy inspection occurs. Option C is wrong because destination port is only a rough hint, not a reliable detection method. Option D is wrong because certificates are used in the SSL/TLS handshake and proxy trust model, but the service’s traffic classification relies on AppID results, not merely reading the server certificate. Reference topics: SSL Proxy, AppID, encrypted session detection, SSL/TLS inspection, application security services.

The correct answer is A. the action taken is defined in the IDP policy that includes this attack object. The exhibit defines a custom attack object named BGP-DEFEND under the security idp custom-attack hierarchy. The custom object includes metadata such as recommended-action drop, severity critical, and signature match conditions such as BGP update AS-path context and pattern 65501. However, an attack object by itself does not determine the final enforcement behavior. The attack object defines what to match; the IDP policy rule that references the object defines what action to take when that match occurs. Juniper describes attack objects as objects used inside IDP rules to identify malicious activity, while IDP rules include rule actions such as drop-packet, drop-connection, close-client, close-server, recommended, and others.

Option B is wrong because the firewall security policy enables IDP inspection by applying an IDP policy, but the IDP action is not selected directly by the normal security policy. Options C and D are too absolute. Even though the custom object shows recommended-action drop, that is only used if the IDP rule action invokes recommended behavior. Without seeing the IDP policy rule action, you cannot conclude reject or drop. Reference topics: IDP custom attack objects, IDP policy rule actions, recommended action, signature-based attack matching.

The correct answers are C and D. The cSRX is Juniper’s containerized SRX firewall, intended for lightweight virtual and container environments where rapid deployment and high density matter. Juniper’s cSRX documentation lists supported security capabilities including basic firewall policy, NAT, Intrusion Detection and Prevention, content security/UTM functions, ATP Cloud, SSL Proxy, AppID, AppFW, and AppTrack. That supports option C, because cSRX provides SRX security services in a containerized footprint rather than requiring a full VM-based firewall appliance.

Option D is also correct because Juniper identifies the cSRX’s small footprint and minimum resource reservation requirements as key benefits; it is designed to scale more densely than VM-based firewall options. Juniper’s Day One cSRX guide specifically identifies faster deployment, a small footprint, and reduced resource consumption as major benefits. Option A is not the best answer for this exam item because the question asks for cSRX deployment benefits, not merely forwarding-mode support. Option B is wrong because the tested cSRX advantage is not a default three-zone configuration. Reference topics: cSRX container firewall, virtual SRX deployment, firewall/NAT/IPS/UTM services, lightweight resource footprint.

The correct answers are A and C. To log denied traffic on an SRX Series Firewall, the security policy must deny the traffic and must generate a log at session initiation. Juniper’s security policy monitoring documentation states that to view logs from denied connections, you enable logging on session-init. Juniper’s traffic-logging guidance also states that for a security policy with a deny action, traffic logs must be generated when a session starts.

Option C is required because the policy action must be deny; otherwise the traffic is not denied by that policy. Option A is required because denied traffic does not complete a normal permitted session lifecycle, so session-init is the correct logging stage for denied connection attempts. Option B, session-close, is used to log permitted sessions after teardown or conclusion; it is not the required parameter for denied traffic. Option D, count, increments policy counters but does not create traffic logs. The correct configuration concept is: match the unwanted traffic, apply then deny, and enable then log session-init. Reference topics: SRX security policies, deny action, session-init logging, traffic log generation, policy counters.

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 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.

The correct answers are C and D. Static attack object groups are manually defined groups. Juniper states that custom attack groups are static in nature because the attacks are explicitly specified in the group; therefore, those attack groups do not change when the security database is updated. This is the key difference between static groups and dynamic groups. Dynamic groups use matching criteria and can automatically update membership when the signature database changes, but static groups do not behave that way.

Option C is correct because updating the IPS/IDP signature database does not automatically add or remove members from a static attack group. Option D is correct because the administrator must explicitly add the desired attack objects to the custom static group. Option A describes dynamic matching behavior, not static group behavior. Option B is also dynamic-group behavior; Juniper Security Director documentation says dynamic group membership is automatically updated during signature updates based on the group’s matching criteria. Static groups are intentionally deterministic: they include only the attacks manually selected by the administrator. Reference topics: IDP attack objects, static attack groups, custom attack groups, dynamic attack groups, IPS signature database updates.

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 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.