JN0-636 Juniper Exam Lab Questions

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)]

According to the output of the command show configuration services security-intelligence url, the SRX Series device is directly enrolled with Juniper ATP Cloud. This is indicated by the URL  , which is the default URL for Juniper ATP Cloud1. This means that the device is not enrolled with Policy Enforcer, which would use a different URL that includes the IP address of the Policy Enforcer server2. Therefore, the problem in this scenario is that the device is directly enrolled with Juniper ATP Cloud, which prevents it from being enrolled with Policy Enforcer.

To enroll the device with Policy Enforcer, the user needs to disenroll the device from Juniper ATP Cloud first. This can be done by using the following command:

delete services security-intelligence url

This command will remove the Juniper ATP Cloud URL from the device configuration and stop the device from receiving threat feeds from Juniper ATP Cloud1. After that, the user can enroll the device with Policy Enforcer by using the Security Director GUI or the SLAX script2.

References: 1: Configuring Juniper ATP Cloud on SRX Series Devices 2: Enrolling SRX Series Devices with Policy Enforcer