Transit traffic is defined as traffic that passes through the SRX (not destined to the Routing Engine). To capture transit traffic:

Sampling and port mirroring (Option D) are the correct supported methods for capturing or exporting transit traffic. Sampling allows captured packets to be sent to a file or collector, while port mirroring sends a copy to a monitoring interface.

Option A: Firewall filters on an egress interface cannot directly capture packets; they can only count, accept, discard, or sample. Sampling itself is separate.

Option B: Loopback interface (lo0) is for control-plane traffic, not transit traffic.

Option C: tcpdump is not supported on SRX as a tool for capturing transit packets; the operational command monitor traffic interface is used, but sampling/port mirroring is the recommended scalable approach.

Correct Method: Sampling and port mirroring

The management functional zone on SRX devices is a special predefined zone with unique characteristics:

It is automatically created (Option C) and cannot be deleted.

It is used specifically for management-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

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.

Juniper security address objects are defined in address books and are used by features such as security policies and NAT. A global address object is valid because Junos supports a global address book that is available across security zones without attaching it to a specific zone. A prefix address object is also valid because Juniper allows addresses to be specified in network prefix format, such as 203.0.113.0/24. Routing address object is not a standard Junos security address-book object type. MAC address object is not the normal address object used for SRX security policy address matching, which primarily uses IPv4, IPv6, DNS, wildcard, and address-range entries.

During web filtering, the SRX first checks local policy elements such as allow lists, block lists, and cached URL categorization information. If the URL is not available locally, the device sends the URL information to the cloud-based web filtering service for categorization. Juniper documentation for enhanced and cloud-based web filtering explains that when the URL is not present in the filtering cache, the device sends a categorization request to the cloud service. NextGen Web Filtering similarly uses the Juniper NGWF cloud to categorize the URL and provide reputation information. Therefore, the correct action is to forward the URL to the NextGen Web Filtering application in the Juniper cloud. It is not simply allowed, blocked, or reset by default before categorization is attempted.

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.

NAT processing in Junos OS follows a strict sequence to ensure correct packet handling:

Static NAT – applied first because it provides a permanent one-to-one bidirectional mapping.

Destination NAT – applied second to translate inbound destination addresses, often used for servers in private networks.

Source NAT – applied last to translate outbound private source addresses to public ones.

This ensures deterministic behavior and avoids conflicts between translation types.

Options B, C, and D list incorrect sequences.

Correct Order: static NAT → destination NAT → source NAT

The exhibit shows the output of show security nat source rule source-NAT-rule-1. The rule belongs to the source NAT rule set and has rule position 1, so it is the first NAT rule in that rule set. The match section shows the source address range as 0.0.0.0 - 255.255.255.255, meaning any IPv4 source address matches. The rule also specifies traffic from the Trust zone to the Untrust zone. Therefore, all traffic entering through the Trust zone and leaving through the Untrust zone matches this source NAT rule. The output also shows translation hits and successful sessions, confirming that traffic has matched the rule. It is not limited to only traffic matching the default route. Juniper documents that NAT rule sets use source/destination zone or interface matching and can be verified with show security nat source rule.

Zone-based security policies are configured in a context that includes both a source zone and a destination zone. Juniper describes this policy context as from-zone to to-zone, and traffic is classified by matching source zone, destination zone, source address, destination address, and application. Option B is therefore correct. Screens are applied earlier in flow processing than policy evaluation, so option A is incorrect. Security policy lookup is part of first path processing when a session is created; once the session exists, fast path traffic normally follows the established session rather than re-evaluating policy for every packet. Option D is also incorrect because zone-based policies can apply to both intra-zone and inter-zone traffic, depending on the configured context.

Avira Antivirus is an on-device antivirus scan engine used by Juniper Content Security on supported SRX Series Firewalls. Juniper documentation states that you must install and activate the Avira Antivirus scan engine and verify that you have an Avira antivirus license before using it. The documentation also states that after configuring Avira as the antivirus type, the device must be rebooted for the new scan engine to take effect. Therefore, a license is required and a reboot is required. Options B and D are incorrect because they contradict Juniper’s Avira Antivirus configuration requirements. After Avira is enabled, Content Security policies and antivirus profiles can be applied to security policies for protocol traffic inspection.