JN0-335 Security - Specialist (JNCIS-SEC) Questions and Answers

• Cluster failovers occur when one node in a chassis cluster becomes inactive or unreachable, and the other node takes over the processing of traffic and services. To control when cluster failovers occur, you can configure two specific parameters on an SRX Series device: heartbeat-interval and heartbeat-threshold12.
• Heartbeat-interval is the time interval, in milliseconds, between heartbeat messages sent by each node to the other node. The default value is 1000 ms. You can configure the heartbeat-interval value from 100 through 3000 ms1.
• Heartbeat-threshold is the number of consecutive heartbeat messages that can be missed before a node is considered to be down. The default value is 3. You can configure the heartbeat-threshold value from 2 through 2551.
• The combination of heartbeat-interval and heartbeat-threshold determines the failover time, which is the maximum time it takes for a node to detect the failure of the other node and initiate a failover. The failover time is calculated as follows: failover time = heartbeat-interval x heartbeat-threshold1.
• For example, if the heartbeat-interval is 1000 ms and the heartbeat-threshold is 3, the failover time is 3000 ms. This means that if a node does not receive three consecutive heartbeat messages from the other node within 3000 ms, it will assume that the other node is down and initiate a failover1.
• You can configure the heartbeat-interval and heartbeat-threshold parameters using the set chassis cluster redundancy-group group-id node node-id priority priority heartbeat-interval interval heartbeat-threshold threshold command1.

References:

• 1: Configuring Chassis Cluster Redundancy Group Properties | Junos OS | Juniper Networks
• 2: Example: Configuring an Active/Passive Cluster Deployment | Junos OS | Juniper Networks

The vSRX is a virtual firewall that offers the same features as the physical SRX Series firewalls, but in a virtualized form factor. It supports next-generation firewall (NGFW) capabilities, networking, and automated lifecycle management. It also integrates with cloud orchestration tools and software-defined networking (SDN) solutions1

The vSRX supports VMXNET3 vNICs, which are optimized for performance in virtualized environments. VMXNET3 vNICs offer enhanced networking features such as jumbo frames, hardware offloads, and multicast filtering2

The vSRX runs on Linux as the base OS, which provides a stable and secure platform for the Junos OS and the firewall functionality. Linux also enables the vSRX to leverage the native hypervisor drivers and APIs for better performance and compatibility3

References: 1: vSRX Virtual Firewall | Juniper Networks US 2: vSRX Virtual Firewall for VMware - TechLibrary - Juniper Networks 3: vSRX Overview - TechLibrary - Juniper Networks

The fab interface is a physical connection between two nodes of a chassis cluster that is used to forward traffic and synchronize session state between the nodes. The fab interface can be any pair of Ethernet interfaces on the same LAN, but they must be the same media type. You need to specify the physical interfaces to be used for the fab link in the configuration, as the system does not determine them automatically. The Junos OS supports only one fab link per node, and it does not support traditional interface features such as IP addressing, routing protocols, or firewall filters. The fab interface is assigned an internally derived IP address by the system for packet transmission. Thefab link also does not support fragmentation, so the MTU size of the fab interface must be equal to or greater than the MTU size of the largest interface in the cluster. References:

• Chassis Cluster Fabric Interfaces
• HA Chassis cluster, difference between Swfab and Fab

References: Unified Security Policies, Understanding Security Policy Elements, Anyone with good understanding of Unified Security Policies (SRX)

Based on the information from the exhibit, node0 is the primary node for both redundancy group 0 (RG0) and redundancy group 1 (RG1). RG0 is responsible for the control plane, which includes the Routing Engine and the management interface. RG1 is responsible for the data plane, which includes the interfaces and services. Therefore, node0 is the active node for the data plane, and node1 is the active node for the control plane34 References:

• Chassis Cluster Redundancy Groups | Junos OS | Juniper Networks
• Troubleshooting a Redundancy Group that Does Not Fail Over in an SRX Chassis Cluster | Junos OS | Juniper Networks
• Understanding Chassis Cluster Redundancy Group 0: Routing Engines | Junos OS | Juniper Networks
• Understanding Chassis Cluster Redundancy Groups 1 Through 128 | Junos OS | Juniper Networks

JIMS (Juniper Identity Management Service) is a standalone Windows service application that collects and maintains a large database of user, device, and group information from Active Directory domains1. You can use JIMS to obtain user identity information and populate the identity management authentication table on SRX Series devices1. You can then use the username or group name in security policies to identify a user and not rely directly on the IP address of the device used2. JIMS also supports integration with ClearPass, which is another solution for user authentication and enforcement2.

ATP Appliance is a solution for advanced threat prevention and detection, not for user and group information. Network Director is a solution for network management and orchestration, not for user and group information. NETCONF is a protocol for network configuration, not for user and group information. References:

• 2: Configure Juniper Identity Management Service to Obtain User Identity Information | Junos OS | Juniper Networks
• 6: Enforce Security Policies using ClearPass | Junos OS | Juniper Networks
• [7]: Juniper Advanced Threat Prevention Appliance | Juniper Networks
• [8]: Network Director | Juniper Networks
• [9]: NETCONF | Junos OS | Juniper Networks

Policy Enforcer is a Junos Space Security Director component that allows updated security policies to be deployed across Juniper SRX Series firewalls, MX Series 5G Universal Routing Platforms, EX Series Ethernet Switches, QFX Series Switches, and third-party network devices1. Policy Enforcer can leverage the DDoS protection feature of Juniper devices to detect and mitigate DDoS attacks on the network. The DDoS protection feature is based on two main components: the classification of host-bound control plane traffic and a hierarchical set of individual- and aggregate-level policers that cap the volume of control plane traffic that each protocol type is able to send to the Routing Engine (RE) for processing2. The DDoS protection feature is supported on MX Series routers and QFX Series switches, among other devices3. Therefore, the correct devices to use for DDoS protection with Policy Enforcer are MX and QFX.

The other options are not correct for the following reasons:

• vQFX is a virtual switch that emulates the QFX Series switches for testing and development purposes. It does not support the DDoS protection feature4.
• vMX is a virtual router that emulates the MX Series routers for testing and development purposes. It does not support the DDoS protection feature.

References: Policy Enforcer DDoS Protection Case Study Protection against distributed denial of service (DDoS) attacks vQFX10000 Overview [vMX Overview]

SSL proxy is a feature that allows SRX Series devices to act as an intermediary between the client and the server for SSL/TLS encrypted traffic. SRX Series devices support two types of SSL proxy: SSL forward proxy and SSL reverse proxy. SSL forward proxy is also known as web proxy or client-protection, and SSL reverse proxy is also known as server-protection1.

SSL forward proxy enables the SRX Series device to decrypt the client-side traffic and apply security policies before re-encrypting and forwarding it to the server. This allows the SRX Series device to inspect the application data and identify the applications and threats in the encrypted traffic2.

SSL reverse proxy enables the SRX Series device to decrypt the server-side traffic and apply security policies before re-encrypting and forwarding it to the client. This allows the SRX Series device to protect the server from malicious clients and provide load balancing and high availability for the server3.

References:

• Configuring SSL Proxy
• SSL Forward Proxy Overview
• SSL Reverse Proxy Overview

The cSRX is a containerized version of the SRX Series device that runs on Linux platforms. The cSRX has the following benefits for deploying in a virtual environment:

• The cSRX supports Layer 2 and Layer 3 deployments, which means it can operate as a transparent or a routed firewall. The cSRX can also support multiple routing instances and virtual routers2
• The cSRX supports firewall, NAT, IPS, and UTM services, which means it can provide comprehensive security features for protecting the virtual network. The cSRX can also support application identification, user firewall, and VPN services2

The cSRX default configuration does not contain three default zones: trust, untrust, and management. The cSRX default configuration contains only one zone: junos-host. The cSRX does not have low memory requirements. The cSRX requires at least 2 GB of memory and 2 CPU cores to run2 References:

• 1: Juniper Security Specialist (JNCIS-SEC) (JN0-334) | Study Guide 3
• 2: Junos OS Security Configuration Guide | cSRX Overview 4

An Application Layer Gateway (ALG) is a software component that is designed to manage specific protocols such as Session Initiation Protocol (SIP) or FTP on Juniper Networks devices running Junos OS. The ALG module is responsible for Application-Layer aware packet processing on switches1. The ALG can perform various functions such as modifying the payload and header of packets, opening secondary connections, translating addresses and ports, and applying security policies1. The ALG does not use software processes for permitting or disallowing specific IP address ranges, as this is the function of firewall filters or security zones2. The ALG does not use software that is used by a single TCP session using the same port numbers as the application, as this is the definition of a stateful firewall3. The ALG does not contain protocols that use one application session for each TCP session, as this is the characteristic of some application protocols such as HTTP or SMTP4. References:

• 1: ALG Overview | Junos OS | Juniper Networks
• 2: Firewall Filters Overview | Junos OS | Juniper Networks
• 3: Stateful Firewall Overview | Junos OS | Juniper Networks
• 4: Application Layer Protocols | Junos OS | Juniper Networks

You can create an exempt rule to skip detection of a set of attacks in certain traffic. You can specify the source and destination IP addresses as the match criteria for the exempt rule. This allows you to exclude traffic from specific hosts or networks from being examined by the IPS rulebase. You can also specify other parameters such as protocol, application, and attack objects for the exempt rule, but source and destination IP addresses are the most common ones. References: = Create IPS or Exempt Rules and rulebase-exempt

• Referring to the exhibit, we can see that the output of the show chassis cluster status command on both nodes shows that they have the same cluster ID, node ID, priority, and status. The status for both nodes is primary, which means that they are both active and ready to process traffic for all redundancy groups1.
• This situation can occur when the control link between the two nodes is down or not configured properly, and the heartbeat messages cannot be exchanged. Without the heartbeat messages, each node assumes that the other node is down and takes over the primary role for all redundancy groups12.
• This is not a desirable state for the cluster, as it can cause traffic disruption, configuration inconsistency, and split-brain scenarios. To resolve this issue, the control link should be checked and fixed, and the cluster should be synchronized12.

References:

• 1: Troubleshooting an SRX Chassis Cluster with One Node in the Primary State and the Other Node in the Disabled State
• 2: SRX Series Chassis Cluster Configuration Overview

 Logging for a security policy can be configured to generate log entries at session initialization, at session close, or both. Logging at session initialization records the initial packet that matches the policy and triggers the session creation. Logging at session close records the summary statistics of the session, such as bytes and packets transmitted and received, and the reason for session termination. Logging at session initialization and close provides the most complete information about the traffic that matches the policy. Logging at fixed intervals, such as every 10 minutes or every 60 seconds, is not supported by Junos OS security policies. References:

• Security, Professional (JNCIP-SEC) Exam Objectives, Firewall Filters section
• Junos OS Security Configuration Guide, Understanding Security Policy Logging section
• Advanced Juniper Security (AJSEC) Course, Chapter 4: Advanced Logging and Reporting

vSRX is a virtual firewall that runs on various hypervisors, such as VMware ESXi, Microsoft Hyper-V, and KVM. vSRX provides security and networking services at the perimeter or edge of virtualized environments. vSRX supports different versions of VMware ESXi, Hyper-V, and KVM, depending on the Junos OS release and the vSRXflavor. Citrix Hypervisor and Oracle VM are not supported hypervisors for vSRX. References:

• vSRX Overview
• Understand vSRX with Microsoft Hyper-V
• Requirements for vSRX Virtual Firewall on VMware
• vSRX Deployment Guide for Microsoft Hyper-V
• vSRX Chassis Cluster/High Availability support for vSRX

References: SSL Proxy Overview Configuring Certificate Authority Profiles Configuring a Root CA Certificate

 The show security policies policy-name detail command shows policy counters for a configured policy. Policy counters display the number of packets and bytes that match the policy, as well as the number of sessions that are created, denied, or closed by the policy. Policy counters can help monitor and troubleshoot the traffic flow and security policy enforcement on the SRX firewall1.

The show security policies policy-name detail command does not display details about the default security policy, which is the implicit policy that is applied when no other policy matches the traffic. The default security policy can be viewed by using the show security policies default-policy command2.

The show security policies policy-name detail command does not identify the different custom policies enabled, which are the user-defined policies that specify the action and conditions for the traffic between zones. The custom policies can be viewed by using the show security policies command without any options1.

The show security policies policy-name detail command does not show the system log files for the local SRX Series device, which are the files that record the events and messages generated by the device. The system log files can be viewed by using the show log command with the name of the file3. References:

• 1: show security policies | Junos OS | Juniper Networks
• 2: Understanding Default Security Policies | Junos OS | Juniper Networks
• 3: show log | Junos OS | Juniper Networks

AppTrack: Tracks and reports applications passing through

the device.

• Intrusion Detection and Prevention (IDP): Applies

appropriate attack objects to applications running on

nonstandard ports. Application identification improves IDP

performance by narrowing the scope of attack signatures

for applications without decoders.

• AppFW: Implements an application firewall using

application-based rules.

• AppQoS: Provides quality-of-service (QoS) prioritization

based on application awareness

The AppSecure AppTrack service module is a logging and reporting tool used to share information about application visibility. Once AppID identifies an application, AppTrack notonly monitors and records its usage, it also sends regular application activity update messages. Since these messages are sent by syslog, they can be read by any compatible third-party device, including Juniper Networks JSA Series Secure Analytics Appliances and Contrail Service Orchestration.https://www.juniper.net/content/dam/www/assets/solution-briefs/us/en/appsecure-application-visibility-and-control.pdf

• Referring to the SRX Series flow module diagram shown in the exhibit, application security is processed at the Services ALGs stage. Application Layer Gateways (ALGs) are software components that enable the SRX Series device to provide application-level security for specific protocols and applications1.
• ALGs inspect the application layer payload of packets and perform various actions, such as modifying the payload, opening pinholes, creating sessions, applying security policies, and enforcing application-specific behavior12.
• ALGs are required for protocols and applications that embed IP address information or port numbers in the application layer data, that open secondary connections, or that are dynamically assigned ports1. Some examples of protocols and applications that require ALGs are FTP, SIP, H.323, RTSP, PPTP, and DNS2.
• ALGs are configured as part of the security policy and are applied to the traffic that matches the policy criteria. ALGs can also be enabled or disabled globally or per zone12.

References:

• 1: Application Layer Gateways Overview
• 2: Application Layer Gateways Feature Guide for Security Devices

 A chassis cluster is a pair of SRX Series devices that are connected and configured to operate as a single node, providing high availability and load balancing for traffic flows1. A chassis cluster consists of two nodes: one primary and one secondary. Each node can host one or more redundancy groups, which are logical entities that group the interfaces and services that need to fail over together in case of a node failure2. Redundancy group 0 is a special group that monitors the control plane of the cluster, such as the routing engine and the control link. Redundancy group 0 is always active on the primary node and standby on the secondary node3. Therefore, option A is false. Each chassis cluster member requires a unique node ID value, which can be either 0 or 1, to identify itself within the cluster4. However, the cluster ID value is the same for both nodes, and it is used to identify the cluster as a whole. Therefore, option B is false. Each chassis cluster member device can host active redundancy groups, depending on the configuration and the status of the nodes. By default, the primary node hosts all the redundancy groups, but you can configure some groups to be preempted by the secondary node if it has a higher priority or load-sharing between the nodes if they have the same priority. Therefore, option C is true. Chassis cluster member devices must be the same model, because different models have different hardware and software specifications that may not be compatible with each other in a cluster. Therefore, option D is true. References:

• Chassis Cluster User Guide for SRX Series Devices
• Understanding Chassis Cluster Redundancy Groups
• Understanding Redundancy Group 0
• Understanding Chassis Cluster Node IDs
• [Understanding Chassis Cluster Cluster IDs]
• [Configuring Chassis Cluster Redundancy Group Settings]
• [Chassis Cluster Feature Guide for SRX Series Devices]

Encrypted Traffic Insights is a feature of Juniper ATP Cloud and SRX Series firewalls that can detect malicious threats that are hidden in encrypted traffic without intercepting and decrypting the traffic. It permits organizations greater visibility and policy control over encrypted traffic, without requiring resource-intensive SSL Decryption1.

Encrypted Traffic Insights assesses the threat of the traffic by using two methods:

• It validates the certificates used by the external servers that the internal hosts are trying to connect to. It compares the certificate signatures with a blocklist of known malicious certificates and also checks the certificate validity, issuer, and subject. If the certificate is invalid or matches a malicious signature, the connection is blocked or alerted2.
• It reviews the timing and frequency of the connections to the external servers. It uses behavior analysis and machine learning to identify patterns and anomalies that indicate malicious activity, such as command and control (C&C) communications, botnet traffic, or data exfiltration. It also uses threat intelligence feeds to enrich the analysis and provide additional context2.

Encrypted Traffic Insights does not decrypt the file or the data in a sandbox or to validate the hash, as these methods would require breaking the encryption of the traffic, which would violate data privacy laws and introduce latency and performance issues21. References:

• 3: SRX5400, SRX5600, SRX5800 Firewalls Datasheet - Juniper Networks
• 2: Encrypted Traffic Insights Overview and Benefits | ATP Cloud | Juniper …
• 1: Juniper Networks Expands Connected Security Portfolio with Encrypted …

Security policy schedulers are a feature that allows you to activate or deactivate a policy for a specified time period. You can create schedulers for a single or recurrent time slot, and apply them to one or more policies. A policy can only have one scheduler associated with it, but a scheduler can have multiple policies associated with it. When a scheduler is active, the policy is available for policy lookup. When a scheduler is inactive, the policy is unavailable for policy lookup. A policy without a defined scheduler will always be active, unless it is explicitly disabled. References:

• Scheduling Security Policies
• schedulers (Security Policies)
• Security Policy Schedulers
• scheduler (Security Policies)

References:

• Security Policies Feature Guide for Security Devices
• Application Security User Guide for Security Devices
• Understanding Micro Application Detection
• Configuring Micro Application Detection
• Content Filtering Feature Guide for Security Devices

Juniper ATP Cloud is a cloud-based threat detection service that protects all hosts in your network against evolving security threats. It assigns a threat level to each attacker IP address from 1 to 10, with 10 being the highest severity. Once the target threshold ismet, Juniper ATP Cloud continues looking for threats for a configurable duration from 0 to 10 minutes. This allows Juniper ATP Cloud to collect more information about the attacker and the attack vector, and to update the threat intelligence accordingly. The other options are incorrect. Option A is not configurable, and option D is not consistent with the documentation. References:

• Juniper Advanced Threat Prevention Cloud | Juniper Networks
• Juniper’s Attacker IP feed bolsters threat protection with SecIntel

AppTrack is a logging and reporting tool that provides statistics for analyzing bandwidth usage of your network. When enabled, AppTrack collects byte, packet, and duration statistics for application flows in the specified zone. AppTrack sends log messages through syslog, providing application activity update messages. AppTrack can be used to share information for application visibility with devices such as Security Threat Response Manager (STRM)12 References:

• 1: Application Tracking | Junos OS | Juniper Networks
• 2: application-tracking | Junos OS | Juniper Networks

Juniper ATP Cloud is a cloud-based threat detection service that protects all hosts in your network against evolving security threats. Juniper ATP Cloud performs the following tasks:

• It extracts potentially malicious objects and files from the traffic and sends them to the cloud for analysis.
• It uses multiple antivirus software packages to analyze files and identify known malicious files quickly. It also uses other techniques, such as machine learning, sandboxing, and behavioral analysis, to identify new malware and add it to the known list of malware.
• It correlates between newly identified malware and known command and control (C&C) sites to aid analysis.
• It blocks known malicious file downloads and outbound C&C traffic.
• It provides features such as DNS, Encrypted Traffic Insights (ETI) and IoT security if you have ATP Cloud premium license.

Based on this information, we can infer the following:

• Option B is correct because Juniper ATP Cloud uses multiple antivirus software packages to analyze files, as well as other techniques, to provide robust coverage against sophisticated, evasive threats.
• Option D is correct because Juniper ATP Cloud does not use antivirus software packages to protect against zero-day threats, which are unknown and undetected by traditional antivirus solutions. Instead, it uses other techniques, such as machine learning, sandboxing, and behavioral analysis, to identify and mitigate zero-day threats.
• Option A is incorrect because Juniper ATP Cloud does not only use one antivirus software package to analyze files, but multiple ones, as well as other techniques.
• Option C is incorrect because Juniper ATP Cloud does not use antivirus software packages to protect against zero-day threats, but other techniques.

References: Juniper Security, Specialist (JNCIS-SEC) Reference Materials and Juniper Security, Professional (JNCIP-SEC) Reference Materials

https://blogs.juniper.net/en-us/security/juniper-strengthens-connected-security-portfolio-with-new-risk-based-access-control-capabilities-and-remote-access-vpn

https://blogs.juniper.net/en-us/security/juniper-strengthens-connected-security-portfolio-with-new-risk-based-access-control-capabilities-and-remote-access-vpn

JIMS server is a Windows service application that collects and maintains user, device, and group information from Active Directory domains or syslog sources. JIMS server uses the Windows event logs to obtain user login and logout information from the domain controllers and Exchange servers. Therefore, to enable JIMS server to view the event logs, you need to perform the following actions:

• Enable remote event log management within Windows Firewall on the necessary domain controllers and Exchange servers. This allows JIMS server to access the event logs on these servers remotely. You can do this by using the Windows Firewall with Advanced Security snap-in or by using the netsh command. For example, to enable remote event log management on a domain controller, you can use the following command:

netsh advfirewall firewall set rule group="Remote Event Log Management" new enable=yes

• Enable remote event log management within Windows Firewall on the JIMS server. This allows JIMS server to receive the event logs from the domain controllers and Exchange servers. You can do this by using the same method as above. For example, to enable remote event log management on the JIMS server, you can use the following command:

netsh advfirewall firewall set rule group="Remote Event Log Management" new enable=yes

Option C and Option D show the correct actions for solving this issue. Option A and Option B are incorrect because they are not related to the JIMS server’s ability to view the event logs. Host-inbound-traffic rules are used to control the traffic that is allowed to reach the SRX Series devices, not the JIMS server. Enabling remote event log management on the Exchange servers is not necessary if JIMS server does not need to collect user information from them.

References: Juniper Security, Specialist (JNCIS-SEC) Reference Materials and Juniper Security, Professional (JNCIP-SEC) Reference Materials