Pass the Juniper JNCIS-SEC JN0-335 Questions and answers with ExamsMirror

References:

[SRX] Behavior of active sessions when modifying a security policy1

In a Juniper Networks chassis clustering setup, when you enable chassis clustering on two devices and assign a cluster ID and a node ID to each device, the correct order for rebooting the devices is: C. Reboot the primary device, then the secondary device. Explanation: After assigning the cluster ID and node ID to each device, it is a good practice to reboot the primary device first. This ensures that the primary device comes online with the specified cluster and node IDs. Once the primary device is up and running, you can then reboot the secondary device. The secondary device will recognize the existing cluster and node IDs assigned to the primary device and join the cluster accordingly.

A reth LAG is a redundant Ethernet interface that includes one or more physical interfaces from each node of a chassis cluster. A reth LAG provides increased bandwidth and link availability for the cluster. To configure a reth LAG, you need to follow these steps:

Configure the physical interfaces on each node as aggregated Ethernet interfaces with the same speed and duplex settings. This is required to ensure that the links can form a LAG andpass traffic correctly. You can use different cable types (such as copper or fiber-optic) for the links, but the speed must be the same.

Configure the reth interface with the redundant-ether-options statement and specify the aggregated Ethernet interfaces as child links. You should have at least two interfaces (one from each node) in the reth LAG, but you can add more for redundancy and load balancing. You can also specify the minimum-links statement to set the minimum number of child links that must be up for the reth interface to be up. The default value is one, but you can change it to a higher value if needed.

Configure the reth interface with the appropriate IP address, security zone, and other settings as needed. You can also enable LACP on the reth interface to dynamically negotiate the LAG parameters with the peer devices.

References:

[Aggregated Ethernet Interfaces in a Chassis Cluster] 1

[Chassis Cluster Redundant Ethernet Interfaces] 2

[LACP / LAG on Chassis Cluster - Interface Monitoring?] 3

[URGENT (LAG - RETH Interconnect)] 4

The vSRX is a virtual firewall that offers the same features as the physical SRX Series firewalls, but in a virtualized form factor for delivering security services that scale to match network demand. It offers the same features as the SRX appliance, including core firewall, robust networking, full next-gen capabilities, and automated life-cycle management1

The vSRX supports Layer 2 and Layer 3 configurations, which means it can operate as a transparent or a routed firewall, depending on the network topology and requirements. The vSRX can also support multiple routing instances, such as virtual routers, virtual switches, and logical systems, to provide logical separation and isolation of traffic2

The vSRX provides clustering, which enables two or more vSRX instances to act as a single, logical device that provides high availability, load balancing, and scalability. The vSRX cluster can synchronize configuration and session information, and support stateful failover and redundancy groups3

The cSRX is a containerized firewall that offers a compact footprint with a high-density firewall for virtualized and cloud environments. It is designed to secure microservices and containerized applications, and provide network visibility and threat prevention4

The cSRX does not support Layer 2 and Layer 3 configurations, as it is intended to be a lightweight and agile firewall that does not perform dynamic routing or networking functions. The cSRX relies on the underlying container orchestration platform, such as Kubernetes or Docker, to provide the network connectivity and management4

The cSRX does not provide clustering, as it is designed to leverage the native resiliency and scalability features of the container orchestration platform. The cSRX can be deployed as a standalone firewall or as part of a service chain, and can be dynamically scaled up or down based on the demand4

The cSRX has faster boot times than the vSRX, as it can be instantiated in seconds, compared to minutes for the vSRX. The cSRX also has a smaller image size and memory requirement than the vSRX, as it is optimized for containerized environments4

The cSRX provides NAT, IPS, and UTM services, similar to the vSRX, but with some limitations. The cSRX does not support IPSec VPN, application identification, user firewall, or SSL proxy. The cSRX also has lower performance and throughput than the vSRX, as it is constrained by the container resources and the orchestration platform4

References: 1: vSRX Virtual Firewall | Juniper Networks US 2: vSRX Virtual Firewall for VMware - TechLibrary - Juniper Networks 3: vSRX Cluster Overview - TechLibrary - Juniper Networks 4: Juniper vSRX versus cSRX - TechLibrary - Juniper Networks

https://www.juniper.net/documentation/us/en/software/csrx/csrx-linux-deployment/topics/concept/security-csrx-docker-overview.html

An Application Layer Gateway (ALG) is a software component that is designed to manage specific protocols such as Session Initiation Protocol (SIP) or FTP on Juniper Networks devices running Junos OS. The ALG module is responsible for Application-Layer aware packet processing on switches1. The ALG can perform various functions such as modifying the payload and header of packets, opening secondary connections, translating addresses and ports, and applying security policies1. The ALG does not use software processes for permitting or disallowing specific IP address ranges, as this is the function of firewall filters or security zones2. The ALG does not use software that is used by a single TCP session using the same port numbers as the application, as this is the definition of a stateful firewall3. The ALG does not contain protocols that use one application session for each TCP session, as this is the characteristic of some application protocols such as HTTP or SMTP4. References:

1: ALG Overview | Junos OS | Juniper Networks

2: Firewall Filters Overview | Junos OS | Juniper Networks

3: Stateful Firewall Overview | Junos OS | Juniper Networks

4: Application Layer Protocols | 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

References: Unified Security Policies, Understanding Security Policy Elements, Anyone with good understanding of Unified Security Policies (SRX)

The fab interface is a physical connection between two nodes of a chassis cluster that is used to forward traffic and synchronize session state between the nodes. The fab interface can be any pair of Ethernet interfaces on the same LAN, but they must be the same media type. You need to specify the physical interfaces to be used for the fab link in the configuration, as the system does not determine them automatically. The Junos OS supports only one fab link per node, and it does not support traditional interface features such as IP addressing, routing protocols, or firewall filters. The fab interface is assigned an internally derived IP address by the system for packet transmission. Thefab link also does not support fragmentation, so the MTU size of the fab interface must be equal to or greater than the MTU size of the largest interface in the cluster. References:

Chassis Cluster Fabric Interfaces

HA Chassis cluster, difference between Swfab and Fab

https://www.juniper.net/documentation/us/en/software/junos/security-iot/topics/topic-map/security-iot-overview.html SRX does not identify the iot device. It streams the metadata to Juniper ATP cloud and Junipe ATP cloud identifies the device.

A: In the vSwitch security settings, accept promiscuous mode. This is a true statement. Promiscuous mode allows the vSwitch to forward all frames to the vSRX control interface, regardless of the destination MAC address1. This is necessary for the control link to function properly and exchange heartbeat messages between the cluster nodes2.

C: In the vSwitch security settings, reject forged transmits. This is also a true statement. Forged transmits are frames that have a source MAC address that is different from the one that is assigned to the vNIC by the host operating system1. Rejecting forged transmits prevents spoofing attacks and ensures that the control link traffic is authentic2.

B: In the vSwitch properties settings, set the VLAN ID to None. This is a false statement. The VLAN ID for the vSwitch can be any value as long as it matches the VLAN ID for the vSRX control interface1. The VLAN ID is used to tag the control link traffic and separate it from other traffic on the same vSwitch2.

D: In the vSwitch security settings, reject MAC address changes. This is also a false statement. MAC address changes are allowed for the vSRX control interface, as the vSRX uses the MAC address of the control link to identify the cluster nodes1. Rejecting MAC address changes would prevent the cluster formation and synchronization2.

References:

1: vSRX Virtual Firewall Cluster Staging and Provisioning for VMware

2: Configuring Chassis Clustering on SRX Series Devices