New Release JN0-335 JNCIS-SEC Questions

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

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

• 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 SRX Series device will drop packets from the infected hosts with a threat level of 8 and no log message will be generated. This is because the security intelligence profile “ATP_Infected-Hosts” has a rule “Rule-1” that matches packets with a threat level of 8 and the action is to block and drop them. There is no log option specified in the action, so no log message will be generated. Options A and B are not correct because the rule only matches packets with a threat level of 8, not 8 or above. Option C is not correct because the action is to drop, not permit, the packets. References: The answer can be verified from Juniper’s official documentation on security intelligence available on their website. Here are some relevant links:

• Security Intelligence Feature Guide for Security Devices
• security-intelligence | Junos OS
• Configure the Security Intelligence Policy on the SRX Series Device