JN0-232 Juniper Security, Associate (JNCIA-SEC) Free Practice Exam Questions (2025 Updated)

License Requirement (Option B):NextGen Web Filtering (NGWF) is a licensed feature on SRX devices. Without a license, the service cannot operate.

Local vs. Cloud Lists (Option C):NGWF checkslocal block/allow lists first. If the URL does not match locally, the request is then checked against the Juniper cloud database.

Option A:Incorrect, since the cloud is only consulted if the URL is not in the local list.

Option D:Incorrect, as NGWF requires a valid subscription/license.

Correct Statements:NGWF requires a license, and it checks local lists before cloud lookup.

NAT rule processing on SRX devices follows a deterministic order:

Top-to-bottom order (Option C):NAT rules are always evaluated in the order they appear in the configuration, starting at the top.

First-match wins (Option B):Once a packet matches a NAT rule, processing stops.

Option A:Incorrect. Not all rules are processed; evaluation stops at the first match.

Option D:Incorrect. NAT rules are never processed bottom-to-top.

Correct Statements:NAT rule processing stops at the first match, and NAT rules are processed top-to-bottom.

Static NAT:Provides a one-to-one bidirectional mapping between internal and external IP addresses. When configured, the translation automatically applies in both directions (Option A is correct). It does not use Port Address Translation (Option C is incorrect).

Destination NAT:Allows external clients to access internal resources by translating the destination address. It supportsport forwardingso specific services (e.g., HTTP on port 80) can be forwarded to an internal host (Option D is correct). It does not require equal-sized address ranges (Option B is incorrect).

Correct Characteristics:Static NAT is bidirectional, and Destination NAT supports port forwarding.

Security Director (Option B):A Junos Space application that provides a centralized interface for managing, monitoring, and maintaining multiple SRX firewalls.

Juniper Secure Analytics (Option A):Focuses on SIEM/log analysis, not centralized firewall management.

Identity Management Service (Option C):Provides user identity integration for policy enforcement, not a management UI.

Secure Connect (Option D):A VPN client solution, not a firewall management platform.

Correct UI:Security Director

Security policies on SRX support several actions:

Permit:Allows traffic to pass according to the rule.

Deny:Silently drops the traffic without notifying the source.

Reject:Drops the trafficand sends a TCP RST (for TCP) or ICMP unreachable (for UDP/other protocols)back to the source. This provides feedback to the sending host.

Next-policy:Allows policy chaining to evaluate the next policy set.

Therefore, the action that causes traffic to drop and a message to be sent to the source isreject.

The packet processing order in SRX with NAT and policies is:

Destination NAT(applies first, for inbound traffic).

Security Policy Evaluation(after destination NAT, before source NAT).

Source NAT(applies last, for outbound traffic).

Option A:Incorrect. Policies are not evaluated before destination NAT.

Option B:Correct. Security policies are evaluatedbefore source NATbut after destination NAT. So in terms of order, policies are processed prior to source NAT.

Option C:Incorrect. Policies are not evaluated before source NAT — they are evaluatedbefore source NAT is applied.

Option D:Correct. Policies are evaluatedafter destination NAT.

Correct Statements:B and D

Screen options are used to detect and prevent attacks such as floods, scans, and malformed packets. In some cases,false positivesmay occur, where legitimate traffic is mistakenly identified as malicious.

To address this, administrators can configure thealarm-without-dropoption (Option D). This setting generates alarms/logs for suspicious traffic without actually dropping it, allowing verification before taking further action.

Enabling all screen options (Option A) may increase false positives further.

Discarding traffic immediately (Option B) risks disrupting legitimate communication.

Increasing sensitivity (Option C) worsens the problem, since false positives would increase.

Correct Action:Use alarm-without-drop to log the traffic without dropping it.

Functional zones(e.g., junos-host, management, null) are not used for forwarding transit traffic. They are used to manage traffic destined to or from the SRX device itself.

Option A:Correct. If traffic enters through a functional zone interface, it is meant for the SRX, not for transit, so it cannot exit another interface.

Option D:Correct. Transit interfaces handle forwarding traffic, but they cannot send that traffic out through a functional zone interface.

Option B and C:Incorrect, because functional zones are strictly control-plane, not transit forwarding zones.

Correct Statements:A and D

Exception traffic is traffic that must be sent from the Packet Forwarding Engine (PFE) to the Routing Engine (RE) for processing, such as routing protocol updates, management traffic, or other control-plane packets. Because the RE is a limited and critical resource, Junos OS implementsrate limiting on exception traffic.

The purpose is toprevent denial-of-service (DoS) attacks on the Routing Engineby controlling the amount of traffic directed to it.

This ensures the RE continues to process control-plane operations reliably, even under potential attack or heavy traffic conditions.

Rate limiting does not enhance forwarding plane performance (Option A), simplify interface configuration (Option B), or manage routing protocols directly (Option D).

Adding interfaces (Option A):An interface must be assigned to a security zone before it can pass traffic. By default, interfaces are in the null zone and cannot send or receive traffic.

Exception traffic (Option B):Security zones define host-inbound-traffic settings, which determine what types of management or control-plane traffic (SSH, ICMP, SNMP) are permitted.

Routing instances (Options C and D):Security zones arespecific to a routing instanceand cannot include interfaces from multiple instances. Therefore, interfaces in the same zone cannot belong to different routing instances.

Correct Statements:A and B

Unified security policies (USPs) provide integrated application-aware controls usingAppIDand extend traditional zone-based policy enforcement.

Option A:Correct. If traffic matches a unified security policy, it is not re-evaluated by traditional security policies. Unified policies take precedence for matched flows.

Option B:Incorrect. Traditional policies rely on Layer 3/4 attributes. Unified policies go deeper by leveraging AppID, which inspects traffic up to Layer 7.

Option C:Incorrect. Traffic matching a traditional policy is unaffected by unified policy unless unified mode is explicitly configured for those flows.

Option D:Correct. Dynamic application recognition in unified policies usesLayer 7 (application-layer) inspectionvia AppID.

Correct Statements:A and D

From the exhibit:

The internal host (172.25.11.101) is located in theTrust zone.

The external address (203.0.113.199/30) is used for communication with the ISP.

The requirement is thatsessions can only be initiated from the external device(the ISP or untrust side) toward the internal host.

This requirement matches the behavior ofDestination NAT:

Destination NAT only (Option A):Maps the external/public IP (203.0.113.199) to the internal/private IP (172.25.11.101). This allows inbound connections to be translated and sent to the internal host. The internal host cannot initiate outbound sessions, since the translation only applies to inbound traffic.

Source NAT only (Option B):Used for outbound sessions from internal private IPs to the Internet. This does not meet the requirement.

Static PAT (Option C):Maps a single port of a public IP to a private IP/port. The exhibit does not indicate a port-based translation.

Static NAT and source NAT (Option D):Would provide bidirectional communication, allowing sessions to be initiated in both directions. This contradicts the requirement.

Correct NAT Type:Destination NAT only

In Junos OS, security zones are the foundation of SRX firewall policy enforcement. Logical interfaces must be assigned to zones. This enables:

Separation of traffic by zone boundaries.

Enforcement ofsecurity policiesfor traffic traversing between zones.

Control of traffic across VLANs, subnets, or functional areas (e.g., trust, untrust, DMZ).

Other options:

Zone assignment is not used to simplify interface configuration (A).

Routing protocols and updates (B) are handled by routing instances, not zones.

SNMP monitoring (D) is enabled under system or services configuration, not zones.

When two networks use the same private IP address ranges, conflicts occur. The solution is to use address translation techniques on the SRX:

NAT (Network Address Translation):Translates private IP addresses to another IP range, enabling connectivity between overlapping private networks.

PAT (Port Address Translation):Extends NAT by allowing multiple private IPs to share one or a few public IPs using different port numbers. This is especially useful when there is a limited pool of public IP addresses.

Other options:

IDP (Option A):Intrusion Detection and Prevention, unrelated to address overlap.

BGP (Option C):A routing protocol, but it does not solve overlapping IP addressing problems.

Correct Features:NAT and PAT

From the exhibit:

The user attempted to access https://www.wikipedia.org.

The block page indicates:

CATEGORY: NG_Reference

REASON: BY_PRE_DEFINED

The header states:“Juniper Web Filtering has been set to block this site.”

Analysis of options:

Option A:Correct. The log shows “REASON: BY_PRE_DEFINED,” which means the site was blocked because it matched apredefined categoryin the Web filtering database.

Option B:Correct. The category “NG_Reference” indicates that theNextGen (Enhanced/Cloud-based) Web Filtering typeis being used.

Option C:Incorrect. The exhibit does not provide any information about SSL proxy configuration; it only shows that the HTTPS site was blocked.

Option D:Incorrect. The block page shown is the standard Juniper default block page, not a custom message.

Correct Statements:The URL matches a predefined Web filtering category, and the NextGen Web Filtering type is being used.

Inbound Flow (before NAT):Source =10.20.30.40(internal private IP)Destination =203.0.113.1(public DNS server)

Outbound Flow (after NAT):Source =192.0.2.1(translated IP)Destination =203.0.113.1(unchanged)

Analysis:

Thesource IP (10.20.30.40)was translated to192.0.2.1. This indicatesSource NATwas applied →Option B is correct.

Thedestination IP changedbetween the inbound and outbound view. Inbound it was203.0.113.1, and outbound it is still203.0.113.1in appearance, but notice the reversal: the session entry shows it as the outbound "source" side. This confirmsDestination NAT translation has occurredfor return flow consistency →Option D is correct.

Option A:Incorrect. The original source IP was indeed translated.

Option C:Incorrect. The destination IP did change in the flow processing.

Correct Statements:

The original source IP address was translated to a new source IP address.

The original destination IP address was translated to a new destination IP address.

Destination NAT purpose (Option C):Used to allow external hosts on the Internet to access internal/private resources (such as a web server in the DMZ). Destination NAT changes the destination IP of incoming traffic to match the internal server.

Pool-based NAT (Option D):SRX supports destination NAT pools, allowing multiple public IP addresses or ranges to be translated to internal servers.

Incorrect options:

Option A describessource NAT, not destination NAT.

Option B is incorrect because SRX does not support “interface-based” destination NAT.

Correct Statements:C and D

Juniper SRX evaluatessecurity policies in order, top to bottom. The first matching policy determines the action, and no further policies are evaluated. This behavior can lead toshadowed policiesif later policies match the same conditions as earlier ones.

From the exhibit:

Policy1:Matches application junos-http and permits traffic.

Policy2:Matches application junos-https and permits traffic.

Policy3:Matches application junos-http again, but denies traffic.

Sincepolicy1already matches all HTTP traffic and permits it, traffic never reachespolicy3. This makespolicy3 shadowedbecause it has the same match condition as policy1 but is evaluated later in the list.

Other options:

Policy1 is not shadowed because it is evaluated first.

Policy2 is independent (application = HTTPS) and therefore unaffected.

Only policy3 is shadowed by policy1.

Correct Statement:Policy3 will be shadowed because it matches the same application as policy1.