The vSRX Virtual Firewall, as a virtualized network function (VNF), is designed for agile and dynamic environments like software-defined networks (SDNs). One of its primary benefits is scalability (A); instances can be rapidly deployed, scaled up, or scaled out to match changing traffic loads and security requirements programmatically. Furthermore, the vSRX provides granular security (C) by leveraging the full suite of Junos OS security features, including AppSecure, intrusion prevention systems (IPS), and advanced policy controls. This allows for detailed traffic inspection and the enforcement of specific security policies, which is critical for implementing micro-segmentation and zero-trust security models within an SDN architecture.

B. no required software license: The vSRX is a commercial product that requires a license to operate and to enable specific features and performance levels.

D. infinite number of interfaces: The number of virtual interfaces on a vSRX is finite and limited by the hypervisor and the specific vSRX software version.

1. Juniper Networks

vSRX Virtual Firewall Data Sheet. This document explicitly highlights the benefits of vSRX. It states

"The vSRX provides a flexible

scalable security solution..." and details its "full next-generation firewall (NGFW) capabilities

" which enable granular security control. (Reference: vSRX Virtual Firewall Data Sheet

"Product Description" and "Features and Benefits" sections).

2. Juniper Networks

"Understanding vSRX with VMware NSX." This documentation

while specific to NSX

describes the role of vSRX in an SDN environment. It emphasizes the ability to "dynamically insert and scale advanced security services

" confirming both scalability and the application of granular security policies in a virtualized network. (Reference: Juniper TechLibrary

"Understanding vSRX with VMware NSX" documentation

Overview section).

3. Juniper Networks

"Contrail Security Overview." In the context of Juniper's own SDN solution

Contrail

the documentation explains how virtual security appliances like the vSRX are used in service chains to provide scalable

on-demand

and detailed (granular) security services for virtual networks. (Reference: Juniper TechLibrary

"Contrail Security Overview

" Service Chaining section).

The fabric (fab) link in a Juniper SRX chassis cluster is a dedicated, high-speed connection responsible for synchronizing real-time objects (RTOs) and forwarding data plane traffic between the two nodes. To ensure optimal performance and low latency for this critical function, the fab link does not support packet fragmentation. The MTU of the physical interfaces used for the fab link must be large enough to handle the largest data packet plus an internal header. Furthermore, the physical interfaces that will serve as the fab link(s) must be explicitly defined in the chassis cluster configuration, binding them to the logical fab0 or fab1 interfaces.

C. The fab link supports traditional interface features.

This is incorrect. The fab link is a special-purpose internal link for cluster synchronization and does not support standard interface features like firewall filters or most Class of Service (CoS) policies.

D. The Junos OS supports only one fab link.

This is incorrect. Junos OS supports configuring up to two fabric links (fab0 and fab1) to provide redundancy and increased bandwidth for the data plane connection between the nodes.

1. Juniper Networks TechLibrary

Chassis Cluster Feature Guide for SRX Series Devices

"Understanding Chassis Cluster Fabric Links". This document states

"The fabric link does not support fragmentation." It also details the purpose of the link

which is distinct from traditional interfaces.

2. Juniper Networks TechLibrary

Junos OS Security Configuration Guide

"Configuring Chassis Cluster Fabric Interfaces (CLI Procedure)". This guide shows the explicit configuration commands required: set chassis cluster fabric-link member-interface

confirming that the physical interface must be specified.

3. Juniper Networks TechLibrary

Chassis Cluster Feature Guide for SRX Series Devices

"Example: Configuring an SRX Series Chassis Cluster". This configuration example explicitly shows the setup for both fab0 and fab1

demonstrating that more than one fab link is supported. For instance

set chassis cluster fabric-link member-interface fab0 member-interface ge-0/0/1 and set chassis cluster fabric-link member-interface fab1 member-interface ge-5/0/1.

Application Quality of Experience (AppQoE) is a feature that monitors application traffic and enforces service level agreements (SLAs) between two endpoints. To enable this functionality, two primary requirements must be met. First, AppQoE must be deployed between two supported Juniper devices, which include both SRX Series Firewalls and MX Series Routers. Second, because AppQoE relies on deep packet inspection to identify applications, a valid application security feature license (which enables AppID) must be installed on the devices. These two elements—supported hardware endpoints and the necessary license—are the foundational prerequisites for enabling AppQoE.

A. You need two SRX Series device endpoints. This is incorrect because it is too restrictive. AppQoE is also supported on MX Series devices, which can act as endpoints.

D. You need to configure AppQoE for reverse traffic. This is a configuration detail within an AppQoE policy, not a prerequisite for enabling the feature itself.

1. Juniper Networks TechLibrary. (2023). Application Quality of Experience (AppQoE) Overview. "AppQoE is supported on SRX Series Firewalls and MX Series 5G Universal Routing Platforms." This statement confirms that both SRX and MX Series devices are supported endpoints.

2. Juniper Networks TechLibrary. (2023). Application Quality of Experience (AppQoE) Overview. "To use AppQoE

you must install the application identification feature license (application security license bundle)." This statement explicitly confirms the license requirement.

Juniper Identity Management Service (JIMS) primarily gathers user-to-IP address mappings by reading security event logs from domain controllers. The domain PC probe is a supplementary mechanism. It is triggered only when JIMS receives a query for an IP address for which it has no user mapping from the event logs. In this scenario, JIMS actively probes the PC at that IP address to determine the logged-in user, thereby resolving the identity.

A: This is incorrect. The PC probe is an active query to an endpoint, not the analysis of domain controller logs. Log analysis is a separate, primary data collection method.

C: This is incorrect. JIMS retrieves user group membership information directly from the Active Directory domain controller using LDAP, not by probing individual PCs.

D: This is incorrect. The information flow is reversed. JIMS initiates the probe to build its identity database; the SRX Series device then queries JIMS for that information.

1. Juniper Networks. (2023). Juniper Identity Management Service (JIMS) Administration Guide.

Reference: In the "Understanding How JIMS Collects User Identity Information" section

it states: "If JIMS does not find a user for an IP address in the event log source

it can probe the PC with that IP address to get the username of the logged-in user." This directly supports option B as the correct trigger for a PC probe.

Reference: The same guide

in the "Configure an Active Directory Source" section

details how JIMS uses LDAP to query for group information

which invalidates option C.

Reference: The overall architecture described in the guide shows the SRX as a client of JIMS

querying it for information. JIMS is the component that actively collects data

invalidating option D.

Encrypted Traffic Insights (ETI), a feature of Juniper ATP Cloud, notifies SRX Series devices about known threats by providing threat intelligence feeds. These feeds contain lists of known malicious sites, such as Command and Control (C&C) servers, which are identified primarily by their domain names. The SRX device subscribes to and downloads these feeds. It then resolves the domain names to their corresponding IP addresses and populates a dynamic address group (DAG) with these IPs. This DAG is then used in security policies to block traffic to and from these malicious sites. The domain name is the core piece of information in the feed that identifies the known malware site.

A. certificates: Certificate metadata is analyzed by ETI to infer threats in encrypted traffic for unknown sites, not as the primary identifier for known malware sites in threat feeds.

B. dynamic address groups: This is the Junos OS mechanism on the SRX that consumes the threat intelligence; it is populated as a result of the notification, not the information used for the notification itself.

C. MAC addresses: These are Layer 2 hardware addresses and are not relevant for identifying or communicating threats from remote Internet-based malware sites.

1. Juniper Networks TechLibrary

Security Director Cloud Documentation

"Encrypted Traffic Insights Overview." This document states

"Encrypted traffic insights uses the following feeds to detect threats: C&C—Juniper ATP Cloud provides a list of C&C servers. The SRX Series device downloads this list and uses it to detect C&C threats." This establishes the use of feeds for known threats.

2. Juniper Networks TechLibrary

Junos OS Documentation

"Understanding Security Intelligence." This guide explains the mechanism: "The Security Intelligence feature allows you to use feeds of IP addresses

URLs

and domain names to protect your network resources from threats... When you configure a feed

the feed entries are loaded into a dynamic address group (DAG)." This explicitly confirms that domain names are a primary type of information in the feeds used to notify the SRX.

3. Juniper Networks TechLibrary

Junos OS Documentation

"Understanding Encrypted Traffic Insights." This document clarifies the process: "The SRX Series device downloads these feeds and populates the IP addresses into a dynamic address group (DAG)." This shows that the information from the feed (which includes domain names) is processed to populate the DAG for enforcement.