Transit traffic is defined as traffic that passesthroughthe 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
Reference:Juniper Networks -Traffic Monitoring and Troubleshooting, Junos OS Security Fundamentals.

* 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.
Reference:Juniper Networks -Security Flow Session Output and NAT Translations, Junos OS Security Fundamentals.

In Junos OS, NAT rules are evaluated intop-down order. When a new rule is added, it is placed at thebottom of the rule set by default.
* To move a rule to the top of the rule set, the command is:
* set security nat source rule-set <name> rule <rule-name> top
* Option A (top):Correct. Moves the specified rule to the top of the list.
* Option B (run):Used to execute operational commands, not rule reordering.
* Option C (up):Not valid for reordering NAT rules.
* Option D (insert):Not a supported NAT reordering command in Junos.
Correct Command:top
Reference:Juniper Networks -NAT Rule Evaluation Order and Rule Reordering, Junos OS Security Fundamentals.

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
Reference:Juniper Networks -Packet Flow Processing Order (NAT and Policies), Junos OS Security Fundamentals.

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
Reference:Juniper Networks -NAT Processing Order, Junos OS Security Fundamentals.