JNCIA-SEC Srx Series Service Gateways Practice Test 4 — 15 Questions

Question 1

Which command is used to save the active configuration changes permanently on an SRX Series gateway running Junos OS?

Accepted Answer

commit. The 'commit' command saves and activates the candidate configuration on Junos devices.

Answer

save configuration

Answer

apply config

Answer

write memory

Question 2

You need to verify the resource utilization of the Routing Engine on an SRX Series gateway, specifically checking CPU load averages and memory usage. Which command should you execute?

Accepted Answer

show chassis routing-engine. The 'show chassis routing-engine' command is the standard Junos operational command that displays Routing Engine status, including CPU load averages (1/5/15 minute), memory utilization (DRAM and installed/available), temperature, uptime, and mastership state. On SRX Series gateways, the Routing Engine handles control-plane functions, so this command is the correct way to verify its resource utilization.

Answer

show spc cpu-utilization

Answer

show security flow status

Answer

show memory summary

Question 3

An administrator is reviewing the packet flow logic on an SRX and wants to understand how unicast Reverse Path Forwarding (uRPF) check is performed. At what point in the packet flow is the uRPF check executed?

Accepted Answer

During the early stage of packet processing, immediately following interface checks and prior to session lookup. uRPF checks the source IP address of an incoming packet against the routing table to verify that the return path matches the ingress interface, occurring early in the flow pipeline after interface checks.

Answer

Only when a session timeout occurs

Answer

After the security policy has completely finished processing

Answer

Inside the NAT translation module

Question 4

You have configured a new security policy on an SRX device, but traffic matching the policy is still being dropped. You check the security logs and see 'POLICY_VIOLATION' or session drop messages. Which command enables real-time packet tracing for security flow debugging?

Accepted Answer

set security flow traceoptions. Flow tracing is enabled using 'set security flow traceoptions file <filename>' and 'set security flow traceoptions flag all' to debug flow mechanics.

Answer

debug security engine

Answer

set firewall filter trace

Answer

monitor traffic interface <name>

Question 5

An administrator is troubleshooting a high-availability cluster issue where the secondary node unexpectedly transitions to 'Ineligible' state. Which command should the administrator run to check the cluster's redundancy group states and interface monitoring status?

Accepted Answer

show chassis cluster status. The command 'show chassis cluster status' provides real-time information on redundancy group states, node prioritization, and monitored interfaces.

Answer

show device-ha state

Answer

show redundancy group details

Answer

show security ha status

Question 6

What is the primary function of Junos security 'Screens' on an SRX Series gateway?

Accepted Answer

Protecting the network against network layer attacks and protocol anomalies (DoS/DDoS mitigation). Screen options provide comprehensive protection against network attacks, such as SYN floods, IP spoofing, and ICMP floods.

Answer

Managing graphical user interface web access

Answer

Encrypting VPN tunnels

Answer

Translating private IP addresses to public IP addresses

Question 7

Which utility or interface provides a browser-based graphical management interface built directly into Junos OS on SRX Series devices?

Accepted Answer

J-Web. J-Web is a browser-based graphical management interface that is built directly into Junos OS on SRX Series devices. It allows administrators to configure, monitor, and manage the device through a web browser without requiring additional software. J-Web is accessed via HTTPS and provides a user-friendly alternative to the CLI.

Answer

Network Director

Answer

Security Director Cloud

Answer

Junos Space

Question 8

You are deploying a vSRX in an AWS or Azure cloud environment and need to configure security zones. How do security zones on a vSRX behave compared to a physical SRX Series gateway?

Accepted Answer

vSRX security zones function identically to physical SRX devices, binding virtual interfaces to zones for policy enforcement.. Security zones on vSRX function identically to physical SRX devices. You bind virtual interfaces to zones, and security policies are enforced based on zone context. The underlying Junos OS security features are the same, ensuring consistent policy enforcement in cloud environments.

Answer

vSRX does not support security zones; it only uses firewall filters.

Answer

vSRX only supports a single default security zone.

Answer

vSRX security zones are managed exclusively through AWS/Azure native security groups.

Question 9

An administrator configures application-based security policies (AppID) on an SRX device. During traffic analysis, they notice that the initial packets of a session are matched against standard port-based policies before AppID determines the specific application. What mechanism explains this behavior?

Accepted Answer

AppID inspects traffic mid-stream after initial session establishment and classification, potentially triggering a policy action change.. AppID on SRX uses a two-phase classification model: the first packet(s) of a session are matched against the initial policy (often port/protocol-based), and once AppID identifies the application via signature inspection, the session may be re-evaluated and the policy action can change. This is why admins see initial packets hit port-based policies before AppID takes over.

Answer

AppID drops all packets until the full file transfer is complete.

Answer

AppID operates entirely in the Routing Engine and bypasses the forwarding plane.

Answer

AppID requires manual application signature compilation via CLI commit.

Question 10

Which Junos command displays active alarms on an SRX Series device, helping you quickly identify hardware faults or system errors?

Accepted Answer

show system alarms. The 'show system alarms' command is the standard Junos operational command that displays all active alarms on an SRX Series device, including chassis, hardware, and system-level alarms. It provides a consolidated view of any conditions that require administrative attention, such as fan failures, power supply issues, or temperature thresholds being exceeded. This is the go-to command for quickly assessing device health and identifying faults.

Answer

show fault status

Answer

show active warnings

Answer

show error logs

Question 11

An administrator sets up a virtual router routing instance on an SRX Series device to isolate customer traffic. How do security policies interact with traffic passing between different routing instances or security zones within virtual routers?

Accepted Answer

Security policies continue to be enforced based on security zone membership, and inter-zone traffic requires explicit policy rules regardless of virtual router boundaries.. Security policies on SRX devices are bound to security zones, and zones can span virtual routers or be assigned per routing instance depending on configuration, requiring explicit inter-zone policies.

Answer

Security policies automatically permit all traffic between virtual routers.

Answer

Virtual routers replace security zones entirely.

Answer

Security policies are bypassed when virtual routers are used.

Question 12

What is the purpose of the 'commit confirmed' command in Junos OS on an SRX Series device?

Accepted Answer

It tests the configuration and applies it temporarily, automatically reverting if not confirmed within a timeout period.. 'commit confirmed' automatically rolls back the configuration if a confirmation command is not issued within a specified time limit, preventing lockout.

Answer

It permanently saves the configuration without any rollback capability.

Answer

It confirms that the hardware is operating correctly.

Answer

It sends an email confirmation of the commit to the admin.

Question 13

Which interface type on an SRX Series device is typically used to connect internal local area networks (LANs) to the security gateway?

Accepted Answer

Gigabit Ethernet (ge- / xe-) interfaces. Gigabit Ethernet (ge-) or similar physical and logical interfaces are used to connect local networks.

Answer

fab0 and fab1

Answer

lc-0/0/0

Answer

fxp0

Question 14

What is the primary role of the Routing Engine (RE) in an enterprise SRX Series gateway?

Accepted Answer

Executing control plane functions, running Junos OS, managing routing protocols, and processing device configuration. The Routing Engine (RE) in an SRX Series gateway is responsible for control plane functions: it runs Junos OS, manages routing protocols, processes configuration, and handles management tasks. It does not forward data traffic; that is the role of the Packet Forwarding Engine (PFE).

Answer

Encrypting IPsec VPN traffic using specialized cryptographic hardware chips

Answer

Processing stateful packet inspection and fast-path data forwarding

Answer

Providing physical Ethernet port switching

Question 15

Which Junos configuration mode command is used to delete an existing configuration statement?

Accepted Answer

delete. In Junos configuration mode, the 'delete' command is used to remove an existing configuration statement. For example, 'delete security policies from-zone trust to-zone untrust policy my-policy' removes that specific policy. The 'delete' command can also be used with wildcards to remove multiple statements. This is a fundamental Junos CLI operation that every administrator must know for managing configurations.

Answer

clear

Answer

remove

Answer

no