Helping Hand Questions for JN0-636

• 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

The appropriate mitigation actions for the selected incident are to block malware IP addresses (download server or CnC server) and to deploy IVP integration (if configured) to confirm if the endpoint has executed the malware and is infected. This is because the incident shows a progression level of “Download” in the kill chain, which means that the malware has been downloaded and is likely to be executed. Blocking the malware IP addresses can prevent further communication with the malicious server and stop the malware from receiving commands or exfiltrating data. Deploying IVP integration can help verify the infection status of the endpoint and provide additional information about the malware behavior and impact. IVP integration is an optional feature that allows the ATP Appliance to interact with third-party endpoint security solutions such as Carbon Black, Cylance, and CrowdStrike. References:

• Advanced Threat Prevention Appliance Solution Brief
• Advanced Threat Prevention Appliance Datasheet
• [Advanced Threat Prevention Appliance Mitigation Actions]
• [Advanced Threat Prevention Appliance IVP Integration]

w.juniper.net/documentation/en_US/junos-space18.1/policy-enforcer/topics/task/configuration/junos-space-policyenforcer-custom-feeds-infected-host-configure.html

The exhibit shows the configuration of filter-based forwarding on an SRX Series device. Filter-based forwarding is a feature that allows the device to use firewall filters to direct traffic to different routing instances based on the match criteria. In this scenario, the device has two routing instances - ISP-1 and ISP-2 - and two firewall filters - FBF and FBF-ISP-1. The FBF filter is applied to the ge-0/0/1 interface as an input filter. The FBF filter has one term that matches the traffic from the 172.25.0.0/24 network and directs it to the ISP-1 routing instance. The ISP-1 routing instance has a static route to the next hop 172.20.0.2. The FBF-ISP-1 filter is applied to the ge-0/0/0 interface as an output filter. The FBF-ISP-1 filter has one term that matches the traffic to the 172.20.0.2 next hop and sets the forwarding class to expedited-forwarding.

The problem in this scenario is that the traffic from the other network (172.25.1.0/24) is not being forwarded to the upstream 172.21.0.2 neighbor. This is because the FBF filter does not have a term that accepts the traffic from the 172.25.1.0/24 network. The FBF filter only has one term that matches the traffic from the 172.25.0.0/24 network and directs it to the ISP-1 routing instance. The traffic from the 172.25.1.0/24 network does not match this term and is therefore discarded by the implicit deny action at the end of the filter. The traffic from the 172.25.1.0/24 network should be forwarded to the ISP-2 routing instance, which has a static default route to the next hop 172.21.0.2.

To solve this problem, you must add another term to the FBF filter to accept the traffic from the 172.25.1.0/24 network. This term should have the action accept, which means that the traffic will be forwarded according to the routing table of the master routing instance. The master routing instance has a static default route to the ISP-2 routing instance, which in turn has a static default route to the next hop 172.21.0.2. By adding this term, the traffic from the 172.25.1.0/24 network will be forwarded to the upstream 172.21.0.2 neighbor as expected.

The configuration of the new term in the FBF filter could look something like this:

[edit firewall family inet filter FBF] term 2 { from { source-address { 172.25.1.0/24; } } then { accept; } }

References: Juniper Security, Professional (JNCIP-SEC) Reference Materials source and documents: