JN0-636 Sample Questions Answers

According to the Juniper documentation, the steps to detect domain generation algorithms (DGA) on an SRX Series firewall are as follows:

• Define a security-metadata-streaming policy under [edit services]. A security-metadata-streaming policy is a configuration that enables the SRX Series firewall to collect and stream security metadata, such as DNS queries and responses, to Juniper ATP Cloud for analysis. Juniper ATP Cloud uses machine learning models and known pre-computed DGA domain names to provide domain verdicts, which helps in-line blocking and sinkholing of DNS queries on SRX Series firewalls1. You can define a security-metadata-streaming policy by using the following command:

set services security-metadata-streaming policy

• Attach the security-metadata-streaming policy to a security zone. A security zone is a logical grouping of interfaces that have similar security requirements. You can attach the security-metadata-streaming policy to a security zone by using the following command:

set security zones security-zone services security-metadata-streaming policy

The following steps are not required or incorrect:

• Define an advanced-anti-malware policy under [edit services]. An advanced-anti-malware policy is a configuration that enables the SRX Series firewall to scan files for malware using Juniper ATP Cloud. It is not related to DGA detection2.
• Attach the advanced-anti-malware policy to a security policy. A security policy is a configuration that defines the rules for permitting or denying traffic between security zones. It is not related to DGA detection3.

References: 1: Configuring Security Metadata Streaming 2: Configuring Advanced Anti-Malware Policies 3: Configuring Security Policies

The Juniper ATP Appliance platform collects, inspects and analyzes advanced and stealthy web, file, and email-based threats that exploit and infiltrate client browsers, operating systems, emails and applications. Juniper ATP Appliance’s detection of malicious attacks generates incident and event details that can be sent to connected SIEM platforms in CEF, LEEF or Syslog formats1. CEF (Common Event Format) is an open log management standard that improves the interoperability of security-related information from different vendors2. Juniper ATP Appliance supports CEF format for sending events and system audit notifications to SIEM servers. You can configure the CEF format in the Juniper ATP Appliance Central Manager WebUI Config > Notifications > SIEM Settings1. Therefore, the correct answer is C. CEF is a supported logging output format for Juniper ATP Appliance. The other options are incorrect because:

• A. WELF (WebTrends Enhanced Log Format) is a proprietary log format developed by WebTrends Corporation for web analytics3. Juniper ATP Appliance does not support WELF format for SIEM integration.
• B. JSON (JavaScript Object Notation) is a lightweight data-interchange format that is easy for humans and machines to read and write4. Juniper ATP Appliance supports JSON format for HTTP API results, but not for SIEM notifications1.
• D. Binary is a numeric system that uses only two digits: 0 and 1. Binary is not a logging output format for Juniper ATP Appliance or any SIEM platform.

References:

• SIEM Syslog, LEEF and CEF Logging
• Common Event Format Configuration Guide
• WebTrends Enhanced Log Format
• JSON

https://www.juniper.net/us/en/products-services/security/advanced-threat-prevention/

• To solve the problem of using the same IPv4 address space as your company, you can identify two neutral IPv4 address spaces for address translation. This will allow you to use the same IPv4 address space as your company without any conflicts. Additionally, you can configure static NAT on the SRX Series devices to ensure that the traffic is properly routed between the two networks.
• Static NAT is a type of network address translation that maps a private IP address to a public IP address on a one-to-one basis. Static NAT is useful when you need to expose a server or device with a private IP address to the Internet or another network with a different IP address range. Static NAT also preserves the original source or destination IP address in the packet header, which can be useful for logging or auditing purposes1.
• Neutral IPv4 address spaces are IP address ranges that are not assigned to any specific organization or entity. They are usually reserved for special purposes, such as private networks, multicast, loopback, or documentation. Neutral IPv4 address spaces can be used for address translation when there is an overlap or conflict between two networks that need to communicate with each other. For example, you can use the 10.0.0.0/8, 172.16.0.0/12, or 192.168.0.0/16 address ranges, which are designated for private use, as neutral IPv4 address spaces for address translation2.

References:

• SRX Getting Started - Configure VPN tunnel for site-to-site connectivity
• SRX & J Series Site-to-Site VPN Configurator
• Resolution Guide – SRX - Troubleshoot Static NAT
• RFC 1918 - Address Allocation for Private Internets

To modify the configuration to fulfill the requirements, you need to modify the log-all term to add the next term action. The other options are incorrect because:

• B. Deleting the log-all term would prevent logging all traffic, which is one of the requirements. The log-all term matches all traffic from any source address and logs it to the system log file1.
• C. Adding a term before the log-all term that blocks Telnet would also prevent logging all traffic, because the log-all term would never be reached. The firewall filter evaluates the terms in sequential order and applies the first matching term. If a term before the log-all term blocks Telnet, then the log-all term would not match any traffic and no logging would occur2.
• D. Applying a firewall filter to the loopback interface that blocks Telnet traffic would not block inbound Telnet traffic on interface ge-0/0/3, which is another requirement. The loopback interface is a logical interface that is always up and reachable. It is used for routing and management purposes, not for filtering traffic on physical interfaces3.

Therefore, the correct answer is A. You need to modify the log-all term to add the next term action. The next term action instructs the firewall filter to continue evaluating the subsequent terms after matching the current term. This way, the log-all term would log all traffic and then proceed to the block-telnet term, which would block only inbound Telnet traffic on interface ge-0/0/34. To modify the log-all term to add the next term action, you need to perform the following steps:

• Enter the configuration mode: user@host> configure
• Navigate to the firewall filter hierarchy: user@host# edit firewall family inet filter block-telnet
• Add the next term action to the log-all term: user@host# set term log-all then next term
• Commit the changes: user@host# commit

References:

• log (Firewall Filter Action)
• Firewall Filter Configuration Overview
• loopback (Interfaces)
• next term (Firewall Filter Action)

• The packet is processed as host inbound traffic because the traceoptions output shows that the destination IP address 10.10.10.1 belongs to the SRX device itself, which is configured with the ge-0/0/1.0 interface. The traceoptions output also shows the flag flow_host_inbound, which indicates that the packet is destined to the device.
• The packet matches the default security policy because the traceoptions output shows that the policy name is default-deny, which is the implicit system-default security policy that denies all packets. The traceoptions output also shows the flag flow_policy_deny, which indicates that the packet is denied by the policy.

References:

• traceoptions (Security NAT) | Junos OS | Juniper Networks
• [SRX] How to interpret Flow TraceOptions output for NAT troubleshooting
• Default Security Policies | Junos OS | Juniper Networks

Referring to the exhibit, your company’s infrastructure team implemented new printers. To make sure that the policy enforcer pushes the updated IP address list to the SRX, you need to perform the following actions:

• A. Configure the server feed URL as http://172.25.10.254/myprinters. The server feed URL is the address of the remote server that provides the custom feed data. You need to configure the server feed URL to match the location of the file that contains the IP addresses of the new printers. In this case, the file name is myprinters and the server IP address is 172.25.10.254, so the server feed URL should be http://172.25.10.254/myprinters1.
• B. Create a security policy that uses the dynamic address feed to allow access. A security policy is a rule that defines the action to be taken for the traffic that matches the specified criteria, such as source and destination addresses, zones, protocols, ports, and applications. You need to create a security policy that uses the dynamic address feed as the source or destination address to allow access to the new printers. A dynamic address feed is a custom feed that contains a group of IP addresses that can be entered manually or imported from external sources. The dynamic address feed can be used in security policies to either deny or allow traffic based on either source or destination IP criteria2.
• C. Configure Security Director to create a dynamic address feed. Security Director is a Junos Space application that enables you to create and manage security policies and objects. You need to configure Security Director to create a dynamic address feed that contains the IP addresses of the new printers. You can create a dynamic address feed by using the local file or the remote file server option. In this case, you should use the remote file server option and specify the server feed URL as http://172.25.10.254/myprinters3.

The other options are incorrect because:

• D. Configuring Security Director to create a C&C feed is not required to complete the requirement. A C&C feed is a security intelligence feed that contains the IP addresses of servers that are used by malware or attackers to communicate with infected hosts. The C&C feed is not related to the new printers or the dynamic address feed.
• E. Configuring the server feed URL as https://172.25.10.254/myprinters is not required to complete the requirement. The server feed URL can use either the HTTP or the HTTPS protocol, depending on the configuration of the remote server. In this case, the exhibit shows that the remote server is using the HTTP protocol, so the server feed URL should use the same protocol1.

References:

• Configuring the Server Feed URL
• Dynamic Address Overview
• Creating Custom Feeds
• [Command and Control Feed Overview]

To share threat intelligence from your environment with third party tools, you need to enable Juniper ATP Cloud to share threat intelligence and configure application tokens in the Juniper ATP Cloud to limit who has access. The other options are incorrect because:

• A. Configuring application tokens in the SRX Series firewalls is not necessary or sufficient to share threat intelligence with third party tools. Application tokens are used to authenticate and authorize requests to the Juniper ATP Cloud API, which can be used to perform various operations such as submitting files, querying C&C feeds, and managing allowlists and blocklists1. However, to share threat intelligence with third party tools, you need to enable the TAXII service in the Juniper ATP Cloud, which is a different protocol for exchanging threat information2.
• D. Enabling SRX Series firewalls to share threat intelligence with third party tools is not possible or supported. SRX Series firewalls can send potentially malicious objects and files to the Juniper ATP Cloud for analysis and receive threat intelligence from the Juniper ATP Cloud to block malicious traffic3. However, SRX Series firewalls cannot directly share threat intelligence with third party tools. You need to use the Juniper ATP Cloud as the intermediary for threat intelligence sharing.

Therefore, the correct answer is B and C. You need to enable Juniper ATP Cloud to share threat intelligence and configure application tokens in the Juniper ATP Cloud to limit who has access. To do so, you need to perform the following steps:

• Enable and configure the TAXII service in the Juniper ATP Cloud. TAXII (Trusted Automated eXchange of Indicator Information) is a protocol for communication over HTTPS of threat information between parties. STIX (Structured Threat Information eXpression) is a language used for reporting and sharing threat information using TAXII. Juniper ATP Cloud can contribute to STIX reports by sharing the threat intelligence it gathers from file scanning. Juniper ATP Cloud also uses threat information from STIX reports as well as other sources for threat prevention2. To enable and configure the TAXII service, you need to select Configure > Threat Intelligence Sharing in the Juniper ATP Cloud WebUI, move the knob to the right to Enable TAXII, and move the slidebar to designate a file sharing threshold2.
• Configure application tokens in the Juniper ATP Cloud. Application tokens are used to authenticate and authorize requests to the Juniper ATP Cloud API and the TAXII service. You can create and manage application tokens in the Juniper ATP Cloud WebUI by selecting Configure > Application Tokens. You can specify the name, description, expiration date, and permissions of each token. You can also revoke or delete tokens as needed. You can use the application tokens to limit who has access to your shared threat intelligence by granting or denying permissions to the TAXII service1.

References:

• Threat Intelligence Open API Setup Guide
• Configure Threat Intelligence Sharing
• About Juniper Advanced Threat Prevention Cloud

The command that will allow traffic to bypass the SRX Series device flow daemon based on the source address is set firewall family inet filter bypass_flowd term t1 then packet-mode. This command configures a stateless firewall filter named bypass_flowd that has one term t1. The term t1 can match the traffic based on the source address or any other criteria. The term t1 then applies the action packet-mode, which means that the traffic will be forwarded using packet-based processing and will not be sent to the flow daemon for stateful inspection. This feature is known as selective stateless packet-based forwarding and it allows you to use both flow-based and packet-based forwarding on the same device for different types of traffic. You can apply the firewall filter to the input or output direction of an interface to enable selective stateless packet-based forwarding for the traffic passing through that interface. References: Juniper Security, Professional (JNCIP-SEC) Reference Materials source and documents: https://www.juniper.net/documentation/en_US/junos/topics/concept/firewall-filter-option-filter-based-forwarding-overview.html https://www.juniper.net/documentation/en_US/junos/topics/example/filter-based-forwarding-example.html

According to the Juniper documentation, filter-based forwarding (FBF) is a technique that allows the SRX Series device to forward packets based on firewall filter rules, rather than the default routing table1. FBF can be used to implement policy-based routing, load balancing, or traffic engineering2. To deploy FBF on the SRX Series device for incoming traffic sourced from the 10.10.100.0/24 network, the following steps are required:

• You must create a forwarding-type routing instance. A forwarding-type routing instance is a special type of routing instance that is used for FBF. It does not have any interfaces or routing protocols associated with it, but it has its own routing table that can be populated by static routes, RIB groups, or routing policies3. You can create a forwarding-type routing instance by using the following command:

set routing-instances instance-type forwarding

• You must create and apply a firewall filter that matches on the source address 10.10.100.0/24 and then sends this traffic to your routing instance. A firewall filter is a set of rules that can match on various packet attributes, such as source and destination addresses, ports, protocols, and so on. You can use the then routing-instance action to specify the routing instance that the packet should be forwarded to4. You can create and apply a firewall filter by using the following commands:

set firewall family inet filter term from source-address 10.10.100.0/24 set firewall family inet filter term then routing-instance  set interfaces unit family inet filter input

• You must create a RIB group that adds interface routes to your routing instance. A RIB group is a mechanism that allows you to import routes from one routing table to another. You can use a RIB group to add the interface routes of the ingress interface to the routing table of the forwarding-type routing instance. This will ensure that the SRX device can forward the packets to the correct next hop based on the destination address5. You can create a RIB group by using the following commands:

set routing-options rib-groups import-rib inet.0 set routing-options rib-groups import-rib .inet.0 set routing-instances routing-options instance-import

The following steps are not required or incorrect:

• You do not need to create a VRF-type routing instance. A VRF-type routing instance is a type of routing instance that is used for virtual routing and forwarding. It allows you to create multiple logical routers on the same physical device, each with its own interfaces, routing protocols, and routing tables. VRF-type routing instances are typically used for VPNs, MPLS, or network segmentation. However, they are not necessary for FBF, which can be achieved with a forwarding-type routing instance.
• You do not need to create and apply a firewall filter that matches on the destination address 10.10.100.0/24 and then sends this traffic to your routing instance. This would be redundant and unnecessary, as the destination address of the incoming traffic is already determined by the routing table of the forwarding-type routing instance. Moreover, this would create a loop, as the traffic would be sent back to the same routing instance that it came from.

References: 1: Filter-Based Forwarding Overview 2: Configuring Filter-Based Forwarding 3: forwarding (Routing Instances) 4: routing-instance (Firewall Filter Action) 5: Configuring RIB Groups : [vrf (Routing Instances)]

 You are connecting two remote sites to your corporate headquarters site. You must ensure that traffic passes through the corporate headquarters. In this scenario, the VPN that should be used is:

• D. Hub-and-spoke IPsec VPN with the corporate firewall acting as the hub device. A hub-and-spoke IPsec VPN is a type of VPN that connects multiple remote sites to a central site, or hub, over a public network. The hub site acts as a gateway for the remote sites and provides security and routing services. The remote sites, or spokes, communicate with each other through the hub site. The hub site and the spoke sites use IPsec tunnels to encrypt and authenticate the traffic between them. A hub-and-spoke IPsec VPN is suitable for connecting two remote sites to your corporate headquarters site, because it allows you to control the traffic flow and enforce security policies at the hub site. The corporate firewall can act as the hub device and provide IPsec VPN services to the remote sites1.

The other options are incorrect because:

• A. Full mesh IPsec VPNs with tunnels between all sites. A full mesh IPsec VPN is a type of VPN that connects every site to every other site over a public network. Each site has an IPsec tunnel with every other site, forming a mesh topology. A full mesh IPsec VPN provides direct and secure communication between any pair of sites, but it also requires a large number of IPsec tunnels and complex configuration. A full mesh IPsec VPN is not suitable for connecting two remote sites to your corporate headquarters site, because it does not ensure that traffic passes through the corporate headquarters site, and it may introduce unnecessary overhead and complexity2.
• B. A full mesh Layer 3 VPN with the BGP route reflector behind the corporate firewall device. A full mesh Layer 3 VPN is a type of VPN that uses MPLS and BGP to provide Layer 3 connectivity and routing between multiple sites over a service provider’s network. Each site has a BGP session with every other site, forming a full mesh topology. A BGP route reflector is a device that reduces the number of BGP sessions required in a full mesh topology by reflecting routes between its clients. A full mesh Layer 3 VPN with the BGP route reflector behind the corporate firewall device is not suitable for connecting two remote sites to your corporate headquarters site, because it does not ensure that traffic passes through the corporate firewall device, and it may require additional configuration and coordination with the service provider3.
• C. A Layer 3 VPN with the corporate firewall acting as the hub device. A Layer 3 VPN is a type of VPN that uses MPLS and BGP to provide Layer 3 connectivity and routing between multiple sites over a service provider’s network. A Layer 3 VPN can have different topologies, such as full mesh, hub-and-spoke, or partial mesh. A Layer 3 VPN with the corporate firewall acting as the hub device is not suitable for connecting two remote sites to your corporate headquarters site, because the corporate firewall may not support MPLS and BGP, and it may require additional configuration and coordination with the service provider3.

References:

• Hub-and-Spoke VPNs Overview
• Full Mesh VPNs Overview
• Layer 3 VPNs Overview

The purpose of the Switch Microservice of Policy Enforcer is to isolate infected hosts. The Switch Microservice is a component of Policy Enforcer that runs on EX Series and QFX Series switches. It communicates with Policy Enforcer and Juniper ATP Cloud to receive threat intelligence and quarantine commands. When an infected host is detected by Juniper ATP Cloud, Policy Enforcer sends a command to the Switch Microservice to isolate the host by applying an access control list (ACL) on the switch port where the host is connected. The ACL blocks all traffic from or to the host except for the traffic that is required for remediation. The Switch Microservice also tracks the MAC address of the infected host and updates Policy Enforcer if the host moves to a different switch port or a different switch. This way, the Switch Microservice ensures that the infected host is isolated until it is remediated and no longer poses a threat to the network. References: Juniper Security, Professional (JNCIP-SEC) Reference Materials source and documents: https://www.juniper.net/documentation/en_US/junos/topics/concept/security-policy-enforcer-switch-microservice-overview.html

https://www.juniper.net/documentation/en_US/junos/topics/topic-map/security-user-auth-configure-jims.html

The security trace options configuration shown in the exhibit is committed to your SRX series firewall. The following statements are correct in this scenario:

• B. Once the trace has generated 10 log files, older logs will be overwritten. The files option in the traceoptions statement specifies the maximum number of trace files to keep. When a trace file reaches its maximum size, it is renamed with a numeric suffix, such as kmd.0, kmd.1, and so on, until the maximum number of files is reached. Then the oldest trace file is overwritten by the newest one. In this case, the files option is set to 10, which means that the trace will generate 10 log files and then overwrite the older ones1.
• D. The file debugger will be readable only by the user who committed this configuration. The file option in the traceoptions statement specifies the name of the trace file and the permissions for the file. The permissions can be either world-readable or owner-readable. In this case, the file option is set to debugger owner-readable, which means that the trace file will be named debugger and will be readable only by the user who committed the configuration1.

The other statements are incorrect because:

• A. The file debugger will not be readable by all users, but only by the user who committed this configuration, as explained above.
• C. The trace will not halt after generating 10 log files, but will continue to overwrite the older ones, as explained above.

References:

• traceoptions (Security)

To troubleshoot the traffic problem using the match criteria, you need to use the show security match-policies CLI command. The other options are incorrect because:

• A. The show security policy-report CLI command displays the policy report, which is a summary of the policy usage statistics, such as the number of sessions, bytes, and packets that match each policy. It does not show the match criteria or the reason why the traffic is not hitting the policy1.
• B. The show security application-tracking counters CLI command displays the application tracking counters, which are the statistics of the application usage, such as the number of sessions, bytes, and packets that match each application. It does not show the match criteria or the reason why the traffic is not hitting the policy2.
• D. The request security policies check CLI command checks the validity and consistency of the security policies, such as the syntax, the references, and the conflicts. It does not show the match criteria or the reason why the traffic is not hitting the policy3.

Therefore, the correct answer is C. You need to use the show security match-policies CLI command to troubleshoot the traffic problem using the match criteria. The show security match-policies CLI command displays the policies that match the specified criteria, such as the source and destination addresses, the zones, the protocols, and the ports. It also shows the action and the hit count of each matching policy. You can use this command to verify if the traffic is matching the expected policy or not, and if not, what policy is blocking or rejecting the traffic4

The two valid modes for the Juniper ATP Appliance are all-in-one and core. The all-in-one mode is a single appliance that performs both the collector and the core functions. The collector function collects traffic from the network and sends it to the core function for analysis and detection. The core function performs the threat detection, mitigation, and analytics. The all-in-one mode is suitable for small to medium-sized networks that do not require high scalability or performance. The core mode is a dedicated appliance that performs only the core function. The core mode is used in conjunction with one or more collector appliances that collect traffic from the network and send it to the core appliance for analysis and detection. The core mode is suitable for large-scale networks that require high scalability and performance. References: Juniper Security, Professional (JNCIP-SEC) Reference Materials source and documents: https://www.juniper.net/documentation/en_US/junos/topics/concept/security-atp-appliance-overview.html

According to the security flow trace shown in the exhibit, which is a snippet of a packet capture on an SRX Series device, the two statements that are correct are:

• This packet arrived on interface ge-0/0/4.0. This is indicated by the line In: 10.0.1.129/22 -> 10.0.1.129/3382;1,0x0, which shows that the ingress interface of the packet is ge-0/0/4.0, as the interface name is prefixed to the source and destination IP addresses and ports of the packet1.
• An existing session is found in the table. This is indicated by the line Found: session id 0x12. sess tok 28685, which shows that the packet matches an existing session in the session table with the session ID 0x12 and the session token 286852.

The following statements are incorrect or not supported by the output:

• Destination NAT occurs. This is not supported by the output, as there is no indication of destination NAT being applied to the packet. The destination IP address of the packet is 10.0.1.129, which is the same as the destination IP address of the original packet. If destination NAT was applied, the destination IP address of the packet would be different from the destination IP address of the original packet.
• The capture is a packet from the source address 172.20.101.10 destined to 10.0.1.129. This is false, as the output shows that the source address of the packet is 10.0.1.129, not 172.20.101.10. The source IP address of the packet is prefixed to the ingress interface name ge-0/0/4.0.

References: 1: Understanding Security Flow Trace 2: show security flow session - Technical Documentation - Support - Juniper Networks

The exhibit shows the output of the show security macsec statistics interface ge-0/0/70 detail command on an SRX Series device. This command displays the statistics for the Media Access Control Security (MACsec) feature on the ge-0/0/70 interface. MACsec is a feature that provides point-to-point security on Ethernet links by using encryption and data integrity checks. MACsec uses two types of keys to secure the traffic: the Connectivity Association Key (CAK) and the Secure Association Key (SAK). The CAK is used for authentication and key exchange between the MACsec peers. The SAK is used for encryption and decryption of the MACsec traffic.

The two statements that are true based on the exhibit are:

• The data that traverses the ge-0/0/70 interface is secured by a secure association key. This is because the exhibit shows that the interface has a Secure Channel (SC) and a Secure Association (SA) established. The SC is a logical connection between the MACsec peers that carries the encrypted traffic. The SA is a subset of the SC that contains the SAK and other parameters for encrypting and decrypting the traffic. The exhibit shows that the interface has encrypted and protected packets, which means that the traffic is secured by the SAK.
• The data that traverses the ge-0/0/70 interface cannot be intercepted and read by anyone. This is because the exhibit shows that the interface has encryption enabled. The encryption option indicates whether the MACsec traffic is encrypted or not. If encryption is enabled, the traffic is encrypted by the SAK and cannot be viewed by anyone monitoring the link. If encryption is disabled, the traffic is only protected by the SAK and can be viewed by anyone monitoring the link.

References: Juniper Security, Professional (JNCIP-SEC) Reference Materials source and documents: https://www.juniper.net/documentation/en_US/junos/topics/reference/command-summary/show-security-macsec-statistics-interface-detail.html https://www.juniper.net/documentation/en_US/junos/topics/concept/security-macsec-overview.html

https://kb.juniper.net/InfoCenter/index?page=content &id=TN326&cat=&actp=LIST&showDraft=false

According to the Juniper documentation, a custom block list feed is a user-defined list of IP addresses or URLs that are considered malicious or unwanted. A custom block list feed can be configured to override the default Juniper Seclntel block list feed, which is a cloud-based service that provides a list of known malicious IP addresses and URLs. To override the Juniper Seclntel block list feed, the custom block list feed must have a higher priority value than the Juniper Seclntel block list feed. In the exhibit, the custom block list feed has a priority value of 10, which is higher than the default priority value of 5 for the Juniper Seclntel block list feed. Therefore, this custom block list feed will be used instead of the Juniper Seclntel block list feed. References: : [Configuring Custom Block List Feeds]

According to the Juniper documentation, reflexive NAT is a type of source NAT that allows an internal host to communicate with an external host using a single public IP address and port. The reflexive NAT session is created when the internal host initiates the traffic to the external host, and the session is deleted when the traffic stops. The reflexive NAT session is bidirectional, meaning that the external host can send traffic back to the internal host using the same public IP address and port that the internal host used to reach the external host. However, the external host cannot initiate a new session to the internal host using the same public IP address and port, unless the internal host has already established a session with the external host. Therefore, only the Internet host that the internal host originally communicated with can initiate traffic to reach the internal host using the 203.0.113.1 address, a random source port, and destination port 54311. References: [Configuring Reflexive NAT]

Proxy ARP is a technique used by routers to answer ARP requests on one network segment on behalf of hosts on another network segment. This is useful in situations where a host on one network segment needs to communicate with a host on another network segment, but the two hosts are not directly connected. In this case, the router acts as a proxy, answering ARP requests on behalf of the other host. In the exhibit, the vSRX device is configured to use a pool of addresses that are in the same subnet as the external interface ge-0/0/0 for source NAT. This means that the vSRX device will translate the source IP address of the internal hosts to one of the addresses in the pool before sending the packets to the external network. However, the external hosts will not know how to reach the NATed addresses, since they are not directly connected to the vSRX device. They will send ARP requests for the NATed addresses, expecting to receive a MAC address from the vSRX device. If proxy ARP is not enabled on the vSRX device, it will not respond to these ARP requests, since it does not have the NATed addresses configured on its interface. The ARP requests will time out and the packets will be dropped by the external hosts or the service provider router. To solve this problem, proxy ARP must be enabled on the vSRX device for the NATed addresses. This will allow the vSRX device to respond to the ARP requests from the external hosts, providing its own MAC address as the destination. The external hosts will then send the packets to the vSRX device, which will reverse the NAT and forward the packets to the internal hosts. References:

• Configuring Proxy ARP (CLI Procedure)
• [SRX] When and how to configure Proxy ARP (https://supportportal.juniper.net/s/article/SRX-Dynamic-VPN-scenario-for-configuring-Proxy-ARP-on-SRX?language=en_US)

You want traffic to avoid the flow daemon for administrative tasks. In this scenario, the two stateless services that are available with selective stateless packet-based services are:

• A. Layer 2 switching. Layer 2 switching is a stateless service that forwards packets based on the MAC addresses of the source and destination hosts. Layer 2 switching does not require any routing or flow processing, and can be performed by the Packet Forwarding Engine (PFE) of the SRX Series device. You can use selective stateless packet-based services to enable Layer 2 switching for traffic that matches a stateless firewall filter. The firewall filter must have the packet-mode action modifier to bypass the flow daemon1.
• B. IPv4 routing. IPv4 routing is a stateless service that forwards packets based on the IP addresses of the source and destination hosts. IPv4 routing does not require any flow processing, and can be performed by the PFE of the SRX Series device. You can use selective stateless packet-based services to enable IPv4 routing for traffic that matches a stateless firewall filter. The firewall filter must have the packet-mode action modifier to bypass the flow daemon1.

The other options are incorrect because:

• C. IPsec. IPsec is a stateful service that provides security and encryption for IP packets. IPsec requires flow processing, and cannot be performed by the PFE of the SRX Series device. You cannot use selective stateless packet-based services to enable IPsec for traffic that matches a stateless firewall filter. The firewall filter cannot have the packet-mode action modifier to bypass the flow daemon2.
• D. IPv6 routing. IPv6 routing is a stateful service that forwards packets based on the IP addresses of the source and destination hosts. IPv6 routing requires flow processing, and cannot be performed by the PFE of the SRX Series device. You cannot use selective stateless packet-based services to enable IPv6 routing for traffic that matches a stateless firewall filter. The firewall filter cannot have the packet-mode action modifier to bypass the flow daemon3.

References:

• Selective Stateless Packet-Based Services Overview
• IPsec VPN Overview
• IPv6 Overview

To control access to network resources based on the identity of an authenticated device on the SRX Series firewalls, you need to perform the following steps:

• A. Configure an end-user-profile that characterizes a device or set of devices. An end-user-profile is a device identity profile that contains a collection of attributes that are characteristics of a specific group of devices, or of a specific device, depending on the attributes configured in the profile. The end-user-profile must contain a domain name and at least one value in each attribute. The attributes include device-identity, device-category, device-vendor, device-type, device-os, and device-os-version1. You can configure an end-user-profile by using the Junos Space Security Director or the CLI2.
• C. Reference the end-user-profile in the security policy. A security policy is a rule that defines the action to be taken for the traffic that matches the specified criteria, such as source and destination addresses, zones, protocols, ports, and applications. You can reference the end-user-profile in the source-end-user-profile field of the security policy to identify the traffic source based on the device from which the traffic issued. The SRX Series device matches the IP address of the device to the end-user-profile and applies the security policy accordingly3. You can reference the end-user-profile in the security policy by using the Junos Space Security Director or the CLI4.
• E. Configure the authentication source to be used to authenticate the device. An authentication source is a system that provides the device identity information to the SRX Series device. The authentication source can be Microsoft Windows Active Directory or a third-party network access control (NAC) system. You need to configure the authentication source to be used to authenticate the device and to send the device identity information to the SRX Series device. The SRX Series device stores the device identity information in the device identity authentication table5. You can configure the authentication source by using the Junos Space Security Director or the CLI6.

The other options are incorrect because:

• B. Referencing the end-user-profile in the security zone is not a valid step to control access to network resources based on the identity of an authenticated device. A security zone is a logical grouping of interfaces that have similar security requirements. You can reference the user role in the security zone to identify the user who is accessing the network resources, but not the end-user-profile7.
• D. Applying the end-user-profile at the interface connecting the devices is also not a valid step to control access to network resources based on the identity of an authenticated device. You cannot apply the end-user-profile at the interface level, but only at the security policy level. The end-user-profile is not a firewall filter or a security policy, but a device identity profile that is referenced in the security policy1.

References:

• End User Profile Overview
• Creating an End User Profile
• source-end-user-profile
• Creating Firewall Policy Rules
• Understanding the Device Identity Authentication Table and Its Entries
• Configuring the Authentication Source for Device Identity
• user-role

According to the output of the traceoptions file called radius, the source of the problem is that the RADIUS server IP address is unreachable. This is indicated by the line FAILURE: sendto: No route to host, which shows that the SRX device cannot send the authentication request to the RADIUS server. This could be due to a network issue, such as a misconfigured route, a firewall blocking the traffic, or a physical link failure.

To troubleshoot this issue, the user should check the following:

• The RADIUS server IP address and port are correctly configured on the SRX device. The user can verify this by using the command show configuration access radius-server1.
• The SRX device can ping the RADIUS server IP address. The user can use the command ping  to test the connectivity2.
• The SRX device has a valid route to the RADIUS server IP address. The user can use the command show route  to check the routing table3.
• The SRX device and the RADIUS server are using the same shared secret key. The user can verify this by using the command show configuration access radius-server secret1.
• The SRX device and the RADIUS server are using the same authentication protocol. The user can verify this by using the command show configuration access profile 4.
• The firewall policies on the SRX device and any intermediate devices are allowing the RADIUS traffic. The user can use the command show security policies from-zone to-zone  to check the firewall policies5.

References: 1: Configuring RADIUS Server Parameters 2: ping - Technical Documentation - Support - Juniper Networks 3: show route - Technical Documentation - Support - Juniper Networks 4: Configuring Authentication Profiles 5: show security policies - Technical Documentation - Support - Juniper Networks

Juniper ATP Cloud performs cache lookup to see if the file is seen already and known to be malicious and dynamic analysis to see what happens if you execute the file in a real environment.

• Cache lookup is one of the functions that Juniper ATP Cloud performs to analyze and detect malware. Cache lookup is the first step in the pipeline approach that Juniper ATP Cloud uses to examine files. Cache lookup checks whether the file has been seen before and whether it has a stored verdict in the database. If the file is known to be malicious, the verdict is returned to the SRX Series Firewall and the file is dropped. If the file is not found in the cache, the analysis continues with the other techniques1.
• Dynamic analysis is another function that Juniper ATP Cloud performs to analyze and detect malware. Dynamic analysis runs the file in a sandbox environment and observes its behavior and actions. Dynamic analysis can reveal the hidden or obfuscated functionality of malware, such as network connections, file modifications, registry changes, and process injections. Dynamic analysis can also detect zero-day threats and evasive malware that try to avoid static analysis1.

References:

• How is Malware Analyzed and Detected? | ATP Cloud | Juniper Networks

Source NAT is a type of NAT that is used to translate the source IP address and port number of a packet. This is typically used to allow multiple devices on a private network to access the internet using a single public IP address. In the exhibit, we can see that the source IP address and port number of the packet are being translated from 10.10.10.2/61606 to 203.0.113.100/179. This is a clear indication that Source NAT is being performed. References:

• Network Address Translation Feature Guide
• SRX NAT with Illustrated Examples

To create a secure fabric in your company’s network, you need to know the following facts:

• A secure fabric is a collection of sites that contain network devices (switches, routers, firewalls, and other security devices) that are used in policy enforcement groups. A site is a grouping of network devices that contribute to threat prevention. When threat prevention policies are applied to policy enforcement groups, the system automatically discovers to which sites those groups belong. This is how threat prevention is aggregated across your secure fabric1.
• MX Series devices associated with tenants can belong to multiple sites. Tenants are logical partitions of the network that can have their own security policies and enforcement points. Sites that are associated with tenants do not need switches as enforcement points, because MX Series devices can perform tenant-based policy enforcement1.
• SRX Series devices can belong to only one site. SRX Series devices are firewalls that can act as perimeter enforcement points for the secure fabric. They can send potentially malicious objects and files to the Juniper ATP Cloud for analysis and receive threat intelligence from the Juniper ATP Cloud to block malicious traffic. SRX Series devices cannot belong to multiple sites, because they do not support tenant-based policy enforcement1.
• A switch must be assigned to the site to enforce an infected host policy within the network. An infected host policy is a policy that blocks or quarantines hosts that are identified as infected by the Juniper ATP Cloud. A switch can act as an internal enforcement point for the secure fabric by applying the infected host policy to the hosts that are connected to it. A switch must be assigned to the site where the infected hosts are located, because SRX Series devices cannot enforce infected host policies1.
• Switches and connectors cannot be added to the same site. Connectors are software agents that can be installed on Windows or Linux servers to enable them to act as enforcement points for the secure fabric. Connectors can apply infected host policies to the hosts that are connected to them. However, connectors cannot coexist with switches in the same site, because they use different methods of policy enforcement. Switches use VLANs and ACLs, while connectors use IPtables and WFP1.

Therefore, the correct answer is B, D, and E. The other options are incorrect because:

• A. MX Series devices associated with tenants can belong to multiple sites, not only one site1.
• C. SRX Series devices can belong to only one site, not multiple sites1.

References:

• Secure Fabric Overview