JN0-335 Exam Dumps : Security, Specialist (JNCIS-SEC)

The cSRX is a containerized version of the SRX Series firewall that provides advanced security services, including content security, AppSecure, and unified threat management (UTM) in the form of a container1. The cSRX supports easy, flexible, and highly scalable deployment options covering various customer use cases, including application protection, microsegmentation, or as an edge gateway for secure IoT deployments through a Docker container management solution2. The cSRX also supports SDN via Contrail Enterprise Multicloud, OpenContrail, and other third-party solutions2. The cSRX also integrates with other next-generation cloud orchestration tools such as Kubernetes3.

The cSRX supports firewall, NAT, IPS, and UTM services, so option A is incorrect1. The cSRX does not only support Layer 2 “bump-in-the-wire” deployments, but also Layer 3 deployments with routing protocols such as BGP, OSPF, and IS-IS, so option B is correct4. The cSRX supports BGP, OSPF, and IS-IS routing services, so option C is correct4. The cSRX does not have three default zones, but instead inherits the zones from the host SRX Series device, so option D is incorrect5. References:

• 1: cSRX Container Firewall | Juniper Networks US
• 2: cSRX Container Firewall Datasheet | Juniper Networks US
• 3: Understanding cSRX with Kubernetes - Juniper Networks
• 4: Extending Security to All Points of Connection: Containerized Security …
• 5: cSRX Container Firewall | Juniper Networks UK&I

• A stateful firewall in SRX Series devices keeps track of the state of network connections, distinguishing legitimate packets for different types of connections and allowing only packets that match a known active connection. Sessions are created when a TCP SYN packet is received and permitted by the security policy1.
• A security policy is a set of rules that defines how traffic is processed by the SRX Series device. A security policy applies the security rules to the transit traffic within a context (from-zone to to-zone) and each policy is uniquely identified by its name. The traffic is classified by matching the source and destination zones, the source and destination addresses, and the application that the traffic carries in its protocol headers with the policy database in the data plane2.
• A Layer 3 route is a path that a packet takes to reach its destination based on the destination IP address. The SRX Series device performs a longest-match Layer 3 route table lookup to determine the next hop for the packet3.
• An Application Layer Gateway (ALG) is a software component that provides application-level awareness, security, and control for specific protocols. An ALG inspects the application-layer payload of a packet and modifies it if necessary to allow the application to traverse the SRX Series device. For example, an ALG can rewrite IP addresses and port numbers in the payload of FTP or SIP packets4.
• The sequence that an SRX Series device uses when implementing stateful session security policies using Layer 3 routes is as follows3:

References:

• 1: Traffic Processing on SRX Series Firewalls Overview | Junos OS | Juniper Networks
• 2: Best Practices for Defining Policies on High-End SRX Series Devices - TechLibrary - Juniper Networks
• 3: [SRX] Example: Configuring TCP SYN Check options on a per-policy basis
• 4: Application Layer Gateways Overview | Junos OS | Juniper Networks

 The error occurred because the “http” application is not defined in this context of Juniper SRX Series device configuration. One solution is to create a custom application named “http” at the [edit applications] hierarchy level (Option C). Another solution is to modify the security policy to use the built-in “junos-http” application which is predefined and doesn’t need an explicit definition (Option D). Options A and B are not correct because they do not address the root cause of the error, which is the undefined application “http”. References: The answers can be verified from Juniper’s official documentation on security policies and applications available on their website. Here are some relevant links:

• Security Policies Feature Guide for Security Devices
• Understanding Applications and Application Sets for SRX Series Devices
• Configuring Custom Applications for SRX Series Devices
• Predefined Applications for SRX Series Devices