Practice Free JN0-335 Security, Specialist (JNCIS-SEC) Exam Questions Answers With Explanation

• 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 for delivering security services that scale to match network demand. It offers the same features as the SRX appliance, including core firewall, robust networking, full next-gen capabilities, and automated life-cycle management1

The vSRX supports Layer 2 and Layer 3 configurations, which means it can operate as a transparent or a routed firewall, depending on the network topology and requirements. The vSRX can also support multiple routing instances, such as virtual routers, virtual switches, and logical systems, to provide logical separation and isolation of traffic2

The vSRX provides clustering, which enables two or more vSRX instances to act as a single, logical device that provides high availability, load balancing, and scalability. The vSRX cluster can synchronize configuration and session information, and support stateful failover and redundancy groups3

The cSRX is a containerized firewall that offers a compact footprint with a high-density firewall for virtualized and cloud environments. It is designed to secure microservices and containerized applications, and provide network visibility and threat prevention4

The cSRX does not support Layer 2 and Layer 3 configurations, as it is intended to be a lightweight and agile firewall that does not perform dynamic routing or networking functions. The cSRX relies on the underlying container orchestration platform, such as Kubernetes or Docker, to provide the network connectivity and management4

The cSRX does not provide clustering, as it is designed to leverage the native resiliency and scalability features of the container orchestration platform. The cSRX can be deployed as a standalone firewall or as part of a service chain, and can be dynamically scaled up or down based on the demand4

The cSRX has faster boot times than the vSRX, as it can be instantiated in seconds, compared to minutes for the vSRX. The cSRX also has a smaller image size and memory requirement than the vSRX, as it is optimized for containerized environments4

The cSRX provides NAT, IPS, and UTM services, similar to the vSRX, but with some limitations. The cSRX does not support IPSec VPN, application identification, user firewall, or SSL proxy. The cSRX also has lower performance and throughput than the vSRX, as it is constrained by the container resources and the orchestration platform4

References: 1: vSRX Virtual Firewall | Juniper Networks US 2: vSRX Virtual Firewall for VMware - TechLibrary - Juniper Networks 3: vSRX Cluster Overview - TechLibrary - Juniper Networks 4: Juniper vSRX versus cSRX - TechLibrary - Juniper Networks

https://www.juniper.net/documentation/us/en/software/csrx/csrx-linux-deployment/topics/concept/security-csrx-docker-overview.html

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)

 To implement IPS on your SRX Series device, you need to download and install the IPS signature database. The IPS signature database contains the attack signatures and predefined attack groups that are used to detect and prevent intrusions. You can download the IPS signature database from the Juniper Networks website or from a local server. You can install the IPS signature database manually or automatically. You do not need to enroll the SRX Series device with Juniper ATP Cloud or reboot the SRX Series device to implement IPS34 References:

• Configuring the IPS Policy on SRX Series Devices Using NSM
• Installing SRX 1400 with IPS activation ??? | SRX - Juniper Networks
• Download an IPS Signature | J-Web for SRX Series 21.2 - Juniper Networks
• IPS Configuration (CLI) | Junos OS | Juniper Networks

Unified policies are security policies that enable you to use dynamic applications as match conditions along with the existing 5-tuple or 6-tuple (with user firewall) match conditions to detect application changes over time3 If the traffic matches the security policy rule, one or more actions defined in the policy are applied to the traffic3 During the initial policy lookup phase, which occurs prior to a dynamic application being identified, if there are multiple policies in the potential policy list, the SRX Series Firewall applies the default security policy until a more explicit match has occurred2 The policy that best matches the application is the final policy2 APPID results are used to determine the final security policy1 References:

• 1: Unified Security Policies | Junos OS | Juniper Networks
• 2: Unified Policies Support for Flow | Junos OS | Juniper Networks
• 3: Unified Policy Overview - TechLibrary - Juniper Networks

The cSRX is a containerized version of the SRX Series firewall that provides advanced security services, including content security, AppSecure, and unified threat management (UTM) in the form of a container1. The cSRX supports easy, flexible, and highly scalable deployment options covering various customer use cases, including application protection, microsegmentation, or as an edge gateway for secure IoT deployments through a Docker container management solution2. The cSRX also supports SDN via Contrail Enterprise Multicloud, OpenContrail, and other third-party solutions2. The cSRX also integrates with other next-generation cloud orchestration tools such as Kubernetes3.

The cSRX supports firewall, NAT, IPS, and UTM services, so option A is incorrect1. The cSRX does not only support Layer 2 “bump-in-the-wire” deployments, but also Layer 3 deployments with routing protocols such as BGP, OSPF, and IS-IS, so option B is correct4. The cSRX supports BGP, OSPF, and IS-IS routing services, so option C is correct4. The cSRX does not have three default zones, but instead inherits the zones from the host SRX Series device, so option D is incorrect5. References:

• 1: cSRX Container Firewall | Juniper Networks US
• 2: cSRX Container Firewall Datasheet | Juniper Networks US
• 3: Understanding cSRX with Kubernetes - Juniper Networks
• 4: Extending Security to All Points of Connection: Containerized Security …
• 5: cSRX Container Firewall | Juniper Networks UK&I

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

The session table is a limited resource for SRX Series devices. If the session table is full, any new sessions will be rejected by the device. The aggressive session-aging mechanism accelerates the session timeout process when the number of sessions in the session table exceeds the specified high-watermark threshold. This mechanism minimizes the likelihood that the SRX Series devices will reject new sessions when the session table becomes full1. To perform aggressive session aging, you need to configure the following parameters1:

• early-ageout –During aggressive session aging, the sessions with an age-out time lower than the early-ageout threshold are marked as invalid. The early-ageout configuration specifies the timeout value, in seconds, that will be applied once the high-watermark value is met. For example, if you set the early-ageout to 30 seconds, any session that has been inactive for at least 30 seconds will be aged out when the high-watermark is reached2.
• high-watermark –The device performs aggressive session aging when the number of sessions in the session table exceeds the high-watermark threshold. The high-watermark configuration specifies the percentage of how much of the session table can be allocated before applying a more aggressive age-out timer. For example, if you set the high-watermark to 90 percent, the device will start aging out sessions more aggressively when the session table reaches 90 percent of its capacity3.

Therefore, the correct statements are B and D.

References: Understanding Aggressive Session Aging high-watermark early-ageout

References:

• [SRX] Behavior of active sessions when modifying a security policy1

Junos OS generates system log messages (also called syslog messages) to record system events that occur on the device, such as routine operations, failure and error conditions, and critical conditions that might require urgent resolution1. System log messages can be sent to different destinations, such as files, remote hosts, userterminals, or the system console2. There are two types of system logs that Junos generates: data plane logs and control plane logs3.

Data plane logs are generated by the Packet Forwarding Engine (PFE), which is responsible for forwarding packets according to the information in the forwarding table. Data plane logs include information about firewall filters, policers, NAT, IPSec, and other features that are applied to the traffic passing through the device4.

Control plane logs are generated by the Routing Engine (RE), which is responsible for running the routing protocols, managing the configuration, and maintaining the routing and forwarding tables. Control plane logs include information about system processes, libraries, services, and applications that run on the device14.

SQL log files and system core dump files are not types of system logs that Junos generates. SQL log files are used by database management systems to store queries and transactions. System core dump files are generated when a process crashes and dumps its memory contents to a file for debugging purposes. References:

• 1: System Logging Overview | Junos OS | Juniper Networks
• 2: syslog (System) | Junos OS | Juniper Networks
• 3: What are two types of system logs that Junos generates? (Choose two …) | Exam4Training
• 4: System Log Messages | Junos OS | Juniper Networks
• [5]: Core dump - Wikipedia

Juniper ATP Cloud is a cloud-based service that provides advanced threat prevention for SRX Series devices. Juniper ATP Cloud can inspect files for malware by sending them to the cloud or performing a hash lookup. To reduce delays in the inspection of files, Juniper ATP Cloud performs the following two functions12:

• Juniper ATP Cloud allows the creation of allowlists. Allowlists are lists of trusted files or domains that are not sent to the cloud for inspection. This reduces the network traffic and the processing time for the files that are known to be safe. You can create allowlists from the Juniper ATP Cloud Web UI or the SRX Series device CLI.
• Juniper ATP Cloud performs a cache lookup on files. Cache lookup is a feature that checks if a file has been previously scanned by Juniper ATP Cloud and returns the cached verdict. This avoids sending the same file to the cloud again and saves bandwidth and time. Cache lookup is enabled by default and can be configured from the SRX Series device CLI. References:
• Juniper ATP Cloud User Guide
• Juniper ATP Cloud Deployment Guide for SRX Series Devices

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

 JSA supports high availability (HA) clusters, which are two JSA hosts that act as a single system. The primary host is the active host and the secondary host is the standby host. If the primary host fails, the secondary host takes over and becomes the active host1 To configure an HA cluster, you must ensure that the software versions on both primary and secondary hosts are the same, and that the cluster virtual IP address is an unused IP address on the same subnet as the primary and secondary hosts1 The secondary host does not backup multiple JSA primary hosts, as each HA cluster consists of only one primary and one secondary host1 The primary and secondary hosts do not need to be configured with the same storage devices, as long as they have enough disk space to store the same amount of data2 References:

• 1: HA Clusters | Junos OS | Juniper Networks
• 2: JSA Virtual Appliance | Juniper Networks US

 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]

JIMS uses eventlogs on Domain contollers or Exchange Servers to determine logon events. So to decrease the load on a Domain Controller you could use the Exchange Server to read logs.

References:

• Juniper Identity Management Service (JIMS) Documentation
• Juniper Identity Management Service User Guide
• Overview | JIMS | Juniper Networks
• Juniper - ExamsBoost
• Juniper Identity Management Service Overview

Juniper Identity Management Service (JIMS) is a service that collects and maintains a large database of user, device, and group information from identity sources, enabling SRX Series Service Gateways to rapidly identify users in a large, distributed enterprise1. JIMS supports the following identity sources: Microsoft Active Directory on Windows Server 2008 R2 and later, and Microsoft Exchange Server 2010 with Service Pack 3 (SP3) and later2. JIMS collects username and device IP addresses from these sources by monitoring the event logs of the Active Directory domain controllers and the Exchange servers3. JIMS does not use DNS or OpenLDAP service ports as identity sources. References:

• Juniper Identity Management Service User Guide, Introduction section
• Supported Identity Sources, Juniper Identity Management Service 1.6.0 Release Notes
• Configure Juniper Identity Management Service to Obtain User Identity Information, Junos OS Security Configuration Guide

• A: In the vSwitch security settings, accept promiscuous mode. This is a true statement. Promiscuous mode allows the vSwitch to forward all frames to the vSRX control interface, regardless of the destination MAC address1. This is necessary for the control link to function properly and exchange heartbeat messages between the cluster nodes2.
• C: In the vSwitch security settings, reject forged transmits. This is also a true statement. Forged transmits are frames that have a source MAC address that is different from the one that is assigned to the vNIC by the host operating system1. Rejecting forged transmits prevents spoofing attacks and ensures that the control link traffic is authentic2.
• B: In the vSwitch properties settings, set the VLAN ID to None. This is a false statement. The VLAN ID for the vSwitch can be any value as long as it matches the VLAN ID for the vSRX control interface1. The VLAN ID is used to tag the control link traffic and separate it from other traffic on the same vSwitch2.
• D: In the vSwitch security settings, reject MAC address changes. This is also a false statement. MAC address changes are allowed for the vSRX control interface, as the vSRX uses the MAC address of the control link to identify the cluster nodes1. Rejecting MAC address changes would prevent the cluster formation and synchronization2.

References:

• 1: vSRX Virtual Firewall Cluster Staging and Provisioning for VMware
• 2: Configuring Chassis Clustering on SRX Series Devices

AppQoS is a service that allows you to prioritize and manage the quality of service (QoS) for different types of applications on SRX Series devices. AppQoS uses application signatures to identify and classify the traffic, and then applies QoS policies to assign bandwidth, priority, and scheduling parameters to the traffic. AppQoS can help you optimize the performance of critical applications, such as VoIP, and ensure that they get the required bandwidth and latency in a congested network12. In this scenario, you can use AppQoS to prioritize the VoIP traffic over other traffic and guarantee its QoS on the SRX Series device at the branch office. References:

• Understanding Application Quality of Service
• Configuring Application Quality of Service

 This is because the error message indicates that the client device does not trust the certificate authority that issued the certificate for the external server. Therefore, you need to import the root CA certificate from the SRX Series device to the client device and add it to the trusted certificate store. This will allow the client device to verify the identity of the SRX Series device and accept the certificates it generates for the external servers3.

The other options are not correct because:

• A. Load a known good, but expired. CA certificate onto the SRX Series device. This will not solve the problem because the client device will still reject the certificates from the SRX Series device if they are signed by an expired CA certificate. The expiration date of the CA certificate is one of the factors that the client device checks when validating the certificate2.
• B. Install a new SRX Series device to act as the client proxy. This will not solve the problem because the new SRX Series device will still need to have a root CA certificate configured and imported to the client devices. The problem is not with the SRX Series device itself, but with the trust relationship between the SRX Series device and the client devices2.
• C. Reboot the SRX Series device. This will not solve the problem because rebooting the SRX Series device will not change the configuration or the certificates on the SRX Series device or the client devices. The problem is not caused by a temporary glitch or a malfunction, but by a mismatch between the certificates on the SRX Series device and the client devices2.

I hope this helps you understand the problem and the solution better. If you want to learn more about SSL client protection proxy, you can check out the following references:

• SSL Proxy Overview
• Configuring SSL Forward Proxy
• Configuring a Root CA Certificate
• SSL Proxy - Client Protection

References: IDP Policy Rules and IDP Rule Bases, rulebase-ips, Exam Name: Security, Specialist (JNCIS-SEC) Version: DEMO - Lead2Pass

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

• B: Chassis cluster member devices synchronize configuration using the control link. The control link is used to exchange control messages and configuration information between the two nodes of a chassis cluster1. The primary node pushes the configuration to the secondary node and ensures that both nodes have the same configuration2.
• C: A control link failure causes the secondary cluster node to be disabled. If the control link fails, the primary node cannot communicate with the secondary node and assumes that the secondary node is down1. The primary node then disables the secondary node and takes over all the traffic processing2.
• E: Heartbeat messages verify that the chassis cluster control link is working. The control link also carries heartbeat messages that are exchanged between the two nodes every 500 milliseconds by default1. The heartbeat messages indicate the status and health of the nodes and the control link2.
• A: Chassis cluster control links must be configured using RFC 1918 IP addresses. This is a false statement. The control link can use any IP address range as long as it is not in conflict with other interfaces or routes on the cluster nodes1. RFC 1918 IP addresses are private addresses that are not routable on the Internet4.
• D: Recovery from a control link failure requires that the secondary member device be rebooted. This is also a false statement. Recovery from a control link failure does not require rebooting the secondary node1. The secondary node can rejoin the cluster when the control link is restored and the configuration is synchronized2.

References:

• 1: Configuring Chassis Clustering on SRX Series Devices
• 2: Chassis Cluster User Guide for SRX Series Devices
• 3: Connecting SRX Series Firewalls to Create a Chassis Cluster
• 4: RFC 1918 - Address Allocation for Private Internets

https://supportportal.juniper.net/s/article/SRX-Secondary-node-of-a-Chassis-Cluster-is-in-Disabled-state-how-do-you-find-the-cause