JN0-231 Security-Associate (JNCIA-SEC) Question and Answers

By default, TCP has a 30-minute idle timeout, and UDP has a 60-second idle timeout. Additionally, known IP protocols have a 30-minute timeout, whereas unknown ones have a 60-second timeout. Setting the inactivity timeout is very useful, particularly if you are concerned about applications either timing out or remaining idle for too long and filling up the session table. According to the Juniper SRX Series Services Guide, this can be configured using the 'timeout inactive' statement for the security policy.

This is necessary to ensure that the application firewall can properly identify the application and the correct security policies can be applied before allowing any traffic to pass through.

If the first packet was allowed to pass without first being identified, then the application firewall would not know which security policies to apply - and this could potentially lead to security vulnerabilities or breaches. So it's important that the first packet is held until the application is identified.

User-defined security zones allow users to configure multiple security zones and share them between routing instances. This allows users to easily manage multiple security zones and their associated policies. For example, a user can create a security zone for corporate traffic, a security zone for guest traffic, and a security zone for public traffic, and then configure policies to control the flow of traffic between each of these security zones. Transit traffic can also be managed using user-defined security zones, as the policies applied to these zones will be applied to the transit traffic as well.

References: https://www.juniper.net/documentation/en_US/junos/topics/task/configuration/security-zones-overview-configuring.html https://www.juniper.net/documentation/en_US/junos/topics/task/security/security-zones-configuring-shared.html

The main purpose of using screens on an SRX Series device is to provide protection against common Denial of Service (DoS) attacks. Screens help prevent network resources from being exhausted or unavailable by filtering or blocking network traffic based on predefined rules. The screens are implemented as part of the firewall function on the SRX Series device, and they help protect against various types of DoS attacks, such as TCP SYN floods, ICMP floods, and UDP floods.

This is because the interface NAT would allow the connections to pass through the firewall - and thus, would ensure that the appropriate ports are open in order to allow for the connections to be established.

This is a really important step in order to ensure that all of the appropriate traffic is allowed through the SRX Series firewall - and thus, it must be a priority when deploying the firewall.

The two statements that are correct about IPsec security associations are that they are bidirectional and that they are established during IKE Phase 2 negotiations. IPsec security associations are bidirectional, meaning that they provide security for both incoming and outgoing traffic. IPsec security associations are established during IKE Phase 2 negotiations, which negotiates the security parameters and establishes the security association between the two peers. For more information, please refer to the Juniper Networks IPsec VPN Configuration Guide, which can be found on Juniper's website.

Juniper Secure Connect client software is supported on the following three operating systems: Windows 7, Windows 10, and macOS. For more information, please refer to the Juniper Secure Connect Administrator Guide, which can be found on Juniper's website. The guide states: "The Juniper Secure Connect client is supported on Windows 7, Windows 10, and macOS." It also provides detailed instructions on how to install and configure the software for each of these operating systems.

Network Prefixes in Address Books

You can specify addresses as network prefixes in the prefix/length format. For example, 203.0.113.0/24 is an acceptable address book address because it translates to a network prefix. However, 203.0.113.4/24 is not acceptable for an address book because it exceeds the subnet length of 24 bits. Everything beyond the subnet length must be entered as 0 (zero). In special scenarios, you can enter a hostname because it can use the full 32-bit address length.

https://www.juniper.net/documentation/us/en/software/junos/security-policies/topics/topic-map/security-address-books-sets.html

https://iosonounrouter.wordpress.com/2018/07/07/how-does-a-flow-based-srx-work/