JN0-232 Security, Associate (JNCIA-SEC) Question and Answers

To enforce acatch-all blocking policyafter other specific policies, the correct solution is aglobal security policy (Option A).

Global policiescan apply universally across zones, and an administrator can configure a final “deny all” rule to block any unmatched traffic.

ATP policy (Option B):Protects against advanced threats, not used for catch-all rule enforcement.

IDP policy (Option C):Focuses on intrusion detection and prevention signatures, not general traffic blocking.

Integrated user firewall policy (Option D):Applies policies based on user identity, but it does not provide a universal block across all services.

Correct Solution:Global security policy

Global security policies extend the flexibility of policy enforcement across the SRX. They are not tied to specific source and destination zones:

From-zone and to-zone contexts are not required(Option A). Global policies apply across all zones unless restricted by match conditions.

Global security policies do not require specific zone contexts(Option B is incorrect).

Global policies areprocessed after zone-based policies, not before. This means that zone-based security policies take precedence (Option C is incorrect).

Administrators can configure bothzone-based security policies and global security policies at the same timeon the same device (Option D is correct).

This allows flexible designs where specific policies can be enforced by zone, while general policies can be applied globally without duplicating rules across multiple zones.

The SRX Series devices support third-party antivirus scanning engines such asAvira. To use the Avira antivirus engine, administrators must explicitly enable the engine and ensure that the required components are properly loaded.

Enable in configuration mode:

The Avira antivirus engine must be enabled under UTM configuration mode. This step ensures the SRX device uses the Avira scanning engine for antivirus inspection.

Example:

set security utm feature-profile anti-virus avira-engine enable

Reboot the SRX device:

A system reboot is required after enabling the Avira engine to load the Avira antivirus components into memory.

Without a reboot, the Avira engine will not become active.

Why not the others?

Restarting themgdprocess (Option A) only reloads the management daemon and does not load antivirus engines.

Enabling inoperational mode(Option B) is not supported; the configuration must be applied in configuration mode.

Therefore, the correct actions to use Avira Antivirus are:Enable the Avira engine in configuration mode (Option D) and reboot the SRX device (Option C).

Multiplerouting instances(such as virtual routers or VRFs) can be configured on an SRX to provide separation of routing tables. This enables:

Maintaining separation of routing information (Option B):Different departments, tenants, or customers can have their own independent routing domains for security and isolation.

SNMP monitoring (Option A) is unrelated to routing instances.

Routing protocols (Option C) can be run inside each instance, but the purpose of multiple instances is separation, not general routing protocol management.

Simplifying interface configuration (Option D) is not a function of routing instances.

Correct Purpose:To maintain separation of routing information for security purposes.

Source NAT (Network Address Translation) is used on SRX devices to allow hosts with private IP addresses to access external networks, such as the Internet. The SRX translates theprivate IP address of the source host into a public IP addressbefore forwarding traffic toward the destination.

It does not translate MAC addresses (Option A).

NAT is unidirectional in this case: it specifically translates private-to-public in the outbound direction, while the reverse (return traffic) is handled automatically through the session table. It is not a bidirectional translation (Option C).

NAT processing occurs as part of the flow module, not limited only to ingress traffic (Option D).

Therefore, the correct statement is that source NAT translatesprivate IP addresses to public IP addresses.

Themanagement functional zoneon SRX devices is a special predefined zone with unique characteristics:

It isautomatically created(Option C) and cannot be deleted.

It is used specifically formanagement-related traffic(Option A), such as SSH, Telnet, web management (J-Web), SNMP, and other control-plane services.

It does not contain revenue (data) interfaces (Option B is incorrect). Interfaces must be explicitly configured into user-defined zones.

The management zone can be referenced in policies if inter-zone communication involving management traffic is needed (Option D is incorrect).

Correct Statements:A and C

Content filtering on SRX devices inspects and controls specific file types transferred across certain application protocols:

SMTP (Option A):Supported. Content filtering can block specific file attachments in emails.

HTTP (Option D):Supported. Content filtering can block downloads of specific file types over web traffic.

SNMP (Option B):Not supported; SNMP is a management protocol, not a content delivery protocol.

TFTP (Option C):Not supported by content filtering.

Correct Protocols:SMTP and HTTP

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).

RFC 1918 defines three private IPv4 blocks:

10.0.0.0/8

172.16.0.0/12

192.168.0.0/16

Option A exactly matches these ranges in a single source NAT rule, replacing numerous per-subnet entries.

Options B and C contain invalid/non-RFC1918 networks (e.g., 192.16.0.0/12, 172.168.0.0/16).

Option D incorrectly adds documentation network192.0.2.0/24, which is not RFC1918.

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

Option B:Correct. Interfaces in the same security zone must belong to the same routing instance; zones cannot span multiple routing instances.

Option D:Correct. A security zone can contain multiple interfaces, allowing grouping of similar trust levels (e.g., multiple LAN subnets in a trust zone).

Option A:Incorrect. An interface can belong to only one zone at a time.

Option C:Incorrect. Interfaces within the same zone cannot be split across routing instances.

Correct Statements:Interfaces in the same zone must share the same routing instance, and a zone can contain multiple interfaces.

SRX Series devices providecontent securityfeatures that rely on advanced identification mechanisms. File identification is not based merely on file extensions (which can be easily spoofed), but instead ondeep inspection techniques:

AppID (Application Identification):AppID is part of the AppSecure suite, allowing the device to classify applications and content regardless of port or protocol. This enables the SRX to detect applications and their related content for enforcement.

Protocol-based file type identification:The SRX can recognize and identify file types embedded withinHTTP, FTP, and e-mail (SMTP, IMAP, POP3) protocols. This providesaccurate content inspection and filtering, independent of file naming conventions.

Why not the others?

File extensions (Option A) are not reliable for content security, so SRX does not use them.

ALGs (Option D) are used for protocol handling, such as SIP or FTP control channels, not for content identification.

Security policies in Junos OS match traffic based on specific criteria:

Source and destination addresses(Option B).

Application(Option D), which may be defined as services (e.g., tcp/80) or recognized through AppID.

Other options:

MAC addresses(Option A) are not used in policy matching; policies operate at Layer 3/4.

Interface name(Option C) is used in firewall filters, not in security policy definitions.

Correct Criteria:Source address and Applications

From the exhibit, the content filter configuration is as follows:

Match Conditions:

Application:HTTP

Direction:download

File-types:exe

Action:

block

notification log

Analysis of Options:

Option A: Incorrect. The configuration specifies thedownload direction, not upload. Uploads of .exe files are unaffected.

Option B: Correct. Because the rule applies todownloads, .exe files will be blocked when users attempt to download them over HTTP.

Option C: Correct. The notification { log; } statement ensures that an entry will be added to the SRX device’s log when the action is triggered.

Option D: Incorrect. No configuration for sending e-mail notifications is shown in the rule. Only logging is specified.

Correct Statements:B and C

PAT (Port Address Translation), also called NAT overload, allows many devices to share a single public IP:

Option C:Correct. Multiple internal hosts share a single external IP.

Option D:Correct. Each internal host is mapped to the same public IP but differentiated by unique port numbers.

Option A:This describes basic static NAT (1-to-1 mapping).

Option B:Incorrect, this describes general NAT behavior but not specific to PAT.

Correct Statements:PAT enables multiple internal devices to share one external IP, and it maps internal IPs to external IP + port.

Afeature profilein a UTM (Unified Threat Management) configuration defines how a specific UTM feature should operate. Examples include:

Anantivirus feature profilethat specifies the type of scanning to perform (streaming or full file-based).

Aweb filtering feature profilethat defines filtering methods, categories, and actions.

Anantispam profilethat defines how spam detection and actions are performed.

Feature profiles do not directly apply to traffic or policies. Instead, they arereferenced inside a UTM policy, and then that policy is applied to a security policy.

Therefore, a feature profile’s purpose is todefine the operation of a specific UTM feature.