Get Juniper JN0-636 Exam Practice Questions - Real and Updated

Answer : C

According to the output shown in the exhibit, which is a security flow session on an SRX Series device, the correct statement is that the local gateway address for the IPsec tunnel is 10.20.20.2. This is indicated by the lineIn: 10.20.20.2/2060 -> 10.20.20.1/3382, which shows that the source IP address of the incoming packet is 10.20.20.2, which is the local gateway address of the IPsec tunnel. The destination IP address of the incoming packet is 10.20.20.1, which is the remote gateway address of the IPsec tunnel.

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

The remote gateway address for the IPsec tunnel is 10.20.20.2. This is false, as explained above. The remote gateway address for the IPsec tunnel is 10.20.20.1, not 10.20.20.2.

The session information indicates that the IPsec tunnel has not been established.This is false, as the output shows that there are two active sessions with the communication tagIPSec VPN: vpn1, which indicates that the IPsec tunnel has been established and is named vpn11.

NAT is being used to change the source address of outgoing packets. This is not supported by the output, as there is no indication of NAT being applied to the outgoing packets. The source IP address of the outgoing packet is 192.168.1.1, which is the same as the source IP address of the original packet. If NAT was being used, the source IP address of the outgoing packet would be different from the source IP address of the original packet.

Answer : A

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 lineFAILURE: 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 commandshow configuration access radius-server1.

The SRX device can ping the RADIUS server IP address.The user can use the commandping <RADIUS-server-IP>to test the connectivity2.

The SRX device has a valid route to the RADIUS server IP address.The user can use the commandshow route <RADIUS-server-IP>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 commandshow 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 commandshow 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 commandshow security policies from-zone <source-zone> to-zone <destination-zone>to check the firewall policies5.

Answer : A, C

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.

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

Answer : C

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; } }

Answer : A, D

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 lineIn: 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 lineFound: 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.