Palo Alto Certifications and Accreditations PCNSE Paloalto Networks Study Notes

The compare option for a specific rule in the New App Viewer under Policy Optimizer allows an administrator to compare the applications configured in the rule with the applications seen from traffic matching the same rule. This helps the administrator to identify any new applications that are not explicitly defined in the rule, but are implicitly allowed by the firewall based on the dependencies of the configured applications. The compare option also shows the usage statistics and risk levels of the applications, and provides suggestions for optimizing the rule by adding, removing, or replacing applications12. References: New App Viewer (Policy Optimizer), PCNSE Study Guide (page 47)

To facilitate the integration with external log parsing systems, the firewall allows you to customize the log format; it also allows you to add custom Key: Value attribute pairs. Custom message formats can be configured under DeviceServer ProfilesSyslogSyslog Server ProfileCustom Log Format.

Step-by-Step

Understanding Log Forwarding in PAN-OS:

Palo Alto Networks firewalls allow forwarding logs to external systems like syslog servers, SNMP servers, or email systems for external analysis or compliance.

Traffic logs can be customized to include additional information that meets the audit or operational requirements.

Syslog Server Profiles:

Syslog Server Profiles specify the format and destination of the log data sent to the syslog server.

These profiles allow customization through the Custom Log Format option, where the firewall engineer can add or modify log fields (e.g., source address, destination address, URL category).

Custom Log Format:

Navigate to Device > Server Profiles > Syslog.

Within the Syslog Server Profile, define a Custom Log Format for traffic logs.

Using this feature, the engineer can include additional fields requested by the internal audit team, such as threat severity, application details, or user ID.

Field Specification:

In the Custom Log Format, fields are defined using variables corresponding to the log fields in PAN-OS.

Example:

$receive_time,$src,$dst,$app,$action,$rule

The engineer can include specific details as requested by the audit team.

Comparison of Other Options:

Option B: Built-in Actions within Objects > Log Forwarding Profile

Log Forwarding Profiles are used to specify what logs are forwarded based on security policy matches. However, they do not control the format of logs.

Log Forwarding Profiles define actions (e.g., forwarding to syslog, SNMP), but customization of log data happens within Syslog Server Profiles.

Option C: Logging and Reporting Settings within Device > Setup > Management

These settings control general logging behavior and settings but do not allow customization of log data for syslog forwarding.

Option D: Data Patterns within Objects > Custom Objects

Data Patterns are used for identifying sensitive data or patterns in data filtering. They are unrelated to log customization.

Why A is Correct?

The Custom Log Format under Device > Server Profiles > Syslog is the only place where additional information can be defined and added to forwarded traffic logs.

This flexibility allows the firewall engineer to meet specific compliance or audit requirements.

Documentation Reference:

PCNSA Study Guide: Logging and Monitoring section discusses Syslog Server Profiles and log forwarding configurations​.

PAN-OS Admin Guide: Covers Custom Log Format configuration under the Syslog Server Profile.

When sizing a decryption firewall deployment, two factors that should be considered are the encryption algorithm and the TLS protocol version. These factors affect the amount of resources and processing power that the firewall needs to decrypt and inspect SSL/TLS traffic.

The encryption algorithm is the method that the server and the client use to encrypt and decrypt the data exchanged in an SSL/TLS session. Different encryption algorithms have different levels of security and performance. For example, AES is a symmetric encryption algorithm that is faster and more efficient than RSA, which is an asymmetric encryption algorithm. However, RSA is more secure than AES because it uses public and private keys to encrypt and decrypt data, while AES uses a single shared key. The firewall must support the encryption algorithms that are used by the servers and clients that it decrypts, and it must have enough CPU and memory resources to handle the decryption workload12.

The TLS protocol version is the standard that defines how the server and the client establish and maintain an SSL/TLS session. Different TLS protocol versions have different features and requirements for encryption algorithms, cipher suites, certificates, handshake messages, etc. For example, TLS 1.3 is the latest and most secure version of TLS, which supports only strong encryption algorithms and cipher suites, such as AES-GCM and ChaCha20-Poly1305, and requires elliptic curve certificates. The firewall must support the TLS protocol versions that are used by the servers and clients that it decrypts, and it must have enough hardware acceleration resources to handle the decryption speed34.

The number of security zones in decryption policies and the number of blocked sessions are not relevant factors for sizing a decryption firewall deployment. The number of security zones in decryption policies only affects how the firewall matches traffic to decryption rules based on source and destination zones, but it does not affect the decryption performance or resource consumption. The number of blocked sessions only indicates how many sessions are denied by the firewall based on security policy or decryption policy rules, but it does not affect the decryption capacity or throughput56.

 Encryption Algorithms, TLS Protocol Versions, Decryption Policy, PCNSE Study Guide (page 60)