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.
Reference:Juniper Networks -Security Policy Evaluation Order and Shadowed Policies, Junos OS Security Fundamentals.

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
Reference:Juniper Networks -Unified Security Policies and AppSecure AppID, Junos OS Security Fundamentals.

After confirming correct routing:
* The next step is toverify security zone assignments (Option A). If interfaces are not correctly assigned to zones, traffic will not be evaluated against proper inter-zone or intra-zone security policies, causing drops.
* Option B:The routing protocol is irrelevant once the correct route lookup is confirmed.
* Option C:NAT is checked later in the flow, not the immediate next step after routing.
* Option D:ALG is only needed for specific applications (FTP, SIP), not general troubleshooting.
Correct Next Step:Verify that interfaces are assigned to the correct security zones.
Reference:Juniper Networks -Packet Flow and Zone-Based Policy Evaluation, Junos OS Security Fundamentals.

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
Reference:Juniper Networks -NAT and Address Overlap Solutions, Junos OS Security Fundamentals.

When a new packet arrives that does not match an existing session, the SRX performs full flow-based processing. After ingress zone determination, the firewall must know the destination zone to evaluate security policies.
* The SRX determines theegress zone by performing a route lookupon the packet's destination IP address.
* The routing decision identifies the outgoing interface, and the zone associated with that interface becomes theegress zone.
* Session lookup (Option A) happens first but is only useful for existing sessions.
* Destination port (Option B) is used for application identification, not zone determination.
* Ingress zone properties (Option D) cannot determine the egress zone.
Reference:Juniper Networks -SRX Series Flow Processing and Security Zone Determination, Junos OS Security Fundamentals.