Top Palo Alto Interview Questions and Answers for 2024

Question 1: How many deployment models are available in Palo Alto?

Answer: Palo Alto offers multiple deployment models:

• Tap Mode: Connects the firewall to a switch SPAN or mirror port, passively collecting and logging traffic.

• Layer 2 Mode: Operates in switching mode, where all interfaces are in the same subnet.

• Layer 3 Mode: Functions like a router, with interfaces in different subnets, supporting routing, static, and dynamic protocols.

• Virtual Wire Mode: No IP or MAC addresses on the interface, functioning transparently.

Question 2: How many Ethernet (physical) and logical interfaces are available in Palo Alto?

Answer:

• Physical Interfaces:

• Tap Mode
• Virtual Wire
• Layer 2
• Layer 3
• Aggregate Interfaces
• HA (High Availability)
• Logical Interfaces:

• VLAN
• Loopback
• Tunnel
• Decrypt Mirror

Question 3: How to publish an internal website to the internet or perform destination NAT?

Answer: To publish an internal website, you need to configure destination NAT and create a firewall policy. This involves converting an internal private IP address to an external public IP address and allowing HTTP access to the internal server. Here’s a typical configuration:

• NAT Configuration: Use pre-NAT configuration to identify zones. Source and destination zones should be Untrust-L3.
• Policy Configuration: Use post-NAT configuration. Source zone is Untrust-L3, and the destination zone is Trust-L3.
• Firewall Rule: Apply pre-NAT IP addresses for source and destination.
• NAT Rule: Configure zones as pre-NAT.
• Security Rule: Configure zones as post-NAT.

Question 4: What is GlobalProtect?

Answer: GlobalProtect provides a transparent agent that extends enterprise security policies to users regardless of location. It can also act as a Remote Access VPN client. Key components include:

• Gateway: Interfaces on Palo Alto firewall providing access and security enforcement.
• Portal: Centralized control managing gateways, certificates, user authentication, and end host checklists.
• Agent: Software on laptops connecting to GlobalProtect deployment.

Question 5: What is HA and how many links are used in HA configuration?

Answer: Palo Alto firewalls use HA (High Availability) links to synchronize data and maintain state information. Key HA links include:

• Control Link (HA1): Exchanges hellos, heartbeats, HA state information, and synchronizes configurations.
• Data Link (HA2): Synchronizes sessions, forwarding tables, IPSec security associations, and ARP tables.
• Backup Links: Provide redundancy for HA1 and HA2 links.
• Packet-Forwarding Link (HA3): Used in active/active deployment for forwarding packets during session setup and asymmetric traffic flow.

Question 6: Which protocol is used to exchange heartbeats between HA pairs?

Answer: ICMP is used to exchange heartbeats between HA pairs in Palo Alto firewalls.

Question 7: How many ports are used in HA?

Answer:

• HA1: TCP/28769 and TCP/28260 for clear text communication, TCP/28 for encrypted communication.
• HA2: Protocol number 99 or UDP-29281.

Question 8: When does failover trigger in Palo Alto?

Answer: Failover triggers when:

1. One or more monitored interfaces fail.
2. Specified destinations cannot be pinged by the active firewall.
3. The active device does not respond to heartbeat polls (three consecutive heartbeat losses over 1000 milliseconds).

Question 9: How to troubleshoot HA issues through CLI?

Answer:

• >show high-availability state: Displays the HA state of the firewall.
• >show high-availability state-synchronization: Checks sync status.
• >show high-availability path-monitoring: Shows path monitoring status.
• >request high-availability state suspend: Suspends the active box and makes the current passive box active.

Question 10: How to test firewall policy matching for a particular destination?

Answer: Use the command: test security-policy-match from trust to untrust destination <IP>

Question 11: How to check the NAT rule?

Answer: Use the command: test nat-policy-match

Question 12: How to check system details?

Answer: Use the command: show system info // It shows management IP, system version, and serial number.

Question 13: How to perform debugging in Palo Alto?

Answer:

1. Clear all packet capture settings: debug dataplane packet-diag clear all
2. Set traffic matching condition: debug dataplane packet-diag set filter match source y.y.y.y destination x.x.x.x
3. Set capture stage:
   • debug dataplane packet-diag set capture stage receive file rx.pcap
   • debug dataplane packet-diag set capture stage transmit file tx.pcap
   • debug dataplane packet-diag set capture stage drop file dp.pcap
   • debug dataplane packet-diag set capture stage firewall file fw.pcap
4. Enable capture: debug dataplane packet-diag set capture on
5. View pcap: view-pcap filter-pcap rx.pcap

Question 14: What do you mean by Device Group and Device Template?

Answer:

• Device Group: Groups firewalls requiring similar policies, like those managing branch offices. Panorama treats each group as a single unit for policy application.
• Device Template: Deploys common base configurations (network and device-specific settings) to multiple firewalls with similar requirements.

Question 15: What is a Security Profile?

Answer: A Security Profile scans allowed applications for threats such as viruses, malware, spyware, and DDoS attacks. Security profiles are not used in traffic flow match criteria but are applied after traffic is allowed by the security policy.

Types of Security Profiles:

• Antivirus Profiles
• Anti-Spyware Profiles
• Vulnerability Protection Profiles
• URL Filtering Profiles
• Data Filtering Profiles
• File Blocking Profiles
• WildFire Analysis Profiles
• DoS Protection Profiles

Question 16: What is the function of a Zone Protection Profile?

Answer: A Zone Protection Profile defends against floods, reconnaissance, packet-based attacks, and non-IP-protocol-based attacks by applying protection measures to each zone based on the aggregate traffic entering the ingress zone.

Question 17: What is the difference between Palo Alto NGFW and WAF?

Answer:

• Palo Alto NGFW: Acts as a primary firewall identifying and controlling applications, users, and content traversing the network. It logs all traffic for analysis and provides high performance for enterprises.
• WAF (Web Application Firewall): Designed to secure web applications by looking for flaws in the application itself and acting on odd behaviors. It focuses on specific Layer 7 fields of web applications and does not inspect other layers in the OSI stack.

Question 18: What is U-Turn NAT?

Answer: U-Turn NAT refers to a scenario where the logical path of a connection traverses the firewall from inside to outside and back in, connecting to an internal resource using its external IP address. It accommodates deployments where external IPs need to reach internal resources.

Question 19: Explain the difference between Virtual Routers and Virtual Systems in Palo Alto?

Answer:

• Virtual Routers (VR): Allow multiple routing tables within a single firewall.
• Virtual Systems (VSYS): Enable partitioning a firewall into multiple logical firewalls, each with its own policies and configuration.

Question 20: How many types of logs can be viewed on Palo Alto NGFWs?

Answer: Types of logs include:

• Traffic Logs
• Threat Logs
• URL Filtering Logs
• WildFire Submissions Logs
• Data Filtering Logs
• Correlation Logs
• Tunnel Inspection Logs
• Config Logs

Question 21: What is WildFire?

Answer: WildFire is a cloud-based service that analyzes files and email links to detect threats. It identifies zero-day malware and generates signatures that Palo Alto firewalls can use to block the malware. Protections are distributed globally within five minutes of threat identification.

Question 22: What is the default IP address and credentials for the management port on a Palo Alto firewall?

Answer: The default IP address is 192.168.1.1, and the default username/password is admin/admin.

Question 23: What is the key difference between a superuser and a device administrator?

Answer:

• Superuser: Has full access to the firewall, including defining new administrator accounts and virtual systems.
• Device Administrator: Has full access to all firewall settings except for defining new accounts or virtual systems.

Question 24: What are the prerequisites for High Availability (HA)?

Answer:

• Same Model
• Same PAN-OS Version
• Same Multi-VSYS Configuration
• Same Interfaces
• Same Set of Licenses

Question 25: How many VPN deployment types does Palo Alto support?

Answer: Palo Alto supports two types of VPN:

• Site-to-Site VPN: Connects branch offices to a central office over the internet.
• Remote Access VPN: Allows individual users to connect remotely to a central network.

Question 26: What interface is used by default to access external services?

Answer: The management (MGT) interface is used by default to access external services, such as DNS servers, external authentication servers, and Palo Alto Networks services.

Question 27: How many zones can an interface be part of?

Answer: An interface can belong to only one zone, although a zone can have multiple interfaces of the same type.

Question 28: Is inter-zone communication blocked by default in Palo Alto?

Answer: Yes, inter-zone communication is blocked by default. A security policy with an Allow action is required to enable communication between security zones.

Question 29: Which file is mandatory for the bootstrap process to function?

Answer: The init-cfg.txt file is mandatory for the bootstrap process, providing bootstrap parameters.

Question 30: Which parameter decides the primary and secondary HA pair?

Answer: The device priority value determines the primary and secondary roles in an HA pair. In active/active configuration, the Device ID is used, with ID 0 being active-primary and ID 1 being active-secondary.

Question 31: What is the Application Command Center (ACC)?

Answer: The Application Command Center (ACC) is an interactive, graphical summary of applications, users, URLs, threats, and content traversing the network. It uses firewall logs to provide visibility into traffic patterns and actionable threat information.

Question 32: What does “incomplete” mean in a traffic log for a new application?

Answer: “Incomplete” means that either the TCP handshake did not complete or there was not enough data after the handshake to identify the application. It indicates that the traffic is not a recognized application.

Question 33: How does Palo Alto firewall forward log messages?

Answer: Log messages can be forwarded to Email Servers, Syslog Servers, SNMP trap servers, or HTTP-based services.

Question 34: When a URL matches multiple categories, which category is chosen?

Answer: The category with the most severe action (block being the most severe and allow the least severe) is chosen when a URL matches multiple categories.

Question 35: What actions are available for filtering URLs?

Answer: The actions, from most strict to least strict, are: block, override, continue, alert, and allow.

Question 36: What is the Captive Portal and its usage?

Answer: The Captive Portal is used to create user-to-IP mappings on the firewall. It triggers based on policies for HTTP and/or HTTPS traffic, and only for IP addresses without existing user-to-IP mapping.

Question 37: How does App-ID identify applications used in the network?

Answer: App-ID identifies applications through multiple techniques, including application signatures, decryption (if needed), protocol decoding, and heuristics. It provides visibility into application usage and behavior, enhancing network security.

Question 38: What are the three focal areas in which Panorama adds value?

Answer: Panorama adds value in:

1. Centralized configuration and deployment.
2. Aggregated logging with central oversight for analysis and reporting.
3. Distributed administration.

Question 39: What are the benefits of using Panorama?

Answer: Panorama allows for bulk software updates with a single click, detailed compliance reporting, and centralized logging. It simplifies managing multiple firewalls and enhances operational efficiency.

Question 40: Which command is used to show the maximum log file size?

Answer: Use the command: show system logdb-quota

Question 41: What are the different failover scenarios in HA?

Answer: Failover scenarios include:

• Hello messages and heartbeat polling: Ensuring the peer firewall is responsive.
• Link monitoring: Tracking the status of physical interfaces.
• Path monitoring: Monitoring network paths to critical IP addresses.
• Administrator suspension or preemption: Manually triggering failover or preemptive role changes.

Question 42: What is the procedure for adding a license to the Palo Alto firewall?

Answer:

1. Obtain license activation codes from Palo Alto Networks customer care.
2. Activate the Support subscription in the web portal (Device > Support).
3. Activate each purchased license (Device > Licenses) using one of the methods:
   • License keys via the license server.
   • Authorization code activation.
   • Manual license key upload.

Question 43: How to take a backup of the Palo Alto firewall?

Answer:

1. Go to Device > Setup > Operations.
2. Click “Save named configuration snapshot” to save settings locally.
3. Click “Export Named Configuration Snapshot” to save a backup to your local PC.

Question 44: Explain Single Pass Software and Parallel Processing Hardware.

Answer:

• Single Pass Software: Executes networking functions, policy lookup, application identification, and threat detection once per packet.
• Parallel Processing Hardware: Ensures fast performance by separating data and control planes, optimizing the firewall’s processing capabilities.

Question 45: What is “service route” in Palo Alto?

Answer: The service route refers to the path from the interface to the server’s service. The management (MGT) interface is the default for accessing external services.

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Question 46: What is Virtual Wire in Palo Alto?

Answer: Virtual Wire mode, also known as VWire, is a deployment mode where the firewall is inserted between two Layer 2 devices without changing the Layer 3 address. It allows the firewall to inspect traffic without being a router or switch, providing transparent security.

Question 47: How does Palo Alto handle SSL/TLS decryption?

Answer: Palo Alto firewalls perform SSL/TLS decryption by intercepting encrypted traffic, decrypting it for inspection, and then re-encrypting it before forwarding to the destination. This process allows the firewall to inspect encrypted traffic for threats and enforce security policies.

Question 48: What is the role of a Decryption Profile in Palo Alto?

Answer: A Decryption Profile in Palo Alto specifies the decryption settings for SSL/TLS traffic. It defines which traffic to decrypt, the certificates to use, and actions for different types of SSL/TLS errors. This profile ensures secure and compliant decryption practices.

Question 49: How does the Palo Alto firewall integrate with SIEM solutions?

Answer: Palo Alto firewalls integrate with SIEM (Security Information and Event Management) solutions by forwarding logs to the SIEM system. This integration allows for real-time analysis, correlation of security events, and comprehensive threat detection and response.

Question 50: What is App-ID and how does it work?

Answer: App-ID is a Palo Alto feature that identifies applications traversing the network, regardless of port, protocol, or encryption. It uses multiple techniques, including application signatures, protocol decoding, and behavioral analysis, to accurately identify and control applications.

Question 51: What is User-ID in Palo Alto?

Answer: User-ID is a Palo Alto feature that links user identity to security policies. It integrates with directory services (like Active Directory) to apply policies based on user roles and groups, providing granular access control and visibility into user activities.

Question 52: How does Palo Alto’s URL Filtering feature work?

Answer: Palo Alto’s URL Filtering feature categorizes websites and controls access based on policies. It blocks access to malicious or inappropriate sites and enforces compliance. The firewall checks URLs against predefined categories and custom policies to determine access permissions.

Question 53: What is the function of the WildFire cloud service?

Answer: WildFire is a cloud-based malware analysis service that detects and blocks unknown threats. It analyzes suspicious files and email links, generates signatures for new malware, and updates firewalls globally to protect against emerging threats.

Question 54: How does Palo Alto manage updates and upgrades?

Answer: Palo Alto manages updates and upgrades through the web interface (Device > Software) or Panorama. Administrators can schedule updates, download new versions, and install them to ensure the firewall has the latest security features and patches.

Question 55: What are the key components of a Palo Alto next-generation firewall (NGFW)?

Answer: Key components include:

• App-ID: Identifies and controls applications.
• User-ID: Links user identity to security policies.
• Content-ID: Protects against threats and data loss.
• SSL Decryption: Inspects encrypted traffic.
• GlobalProtect: Extends security to remote users.
• WildFire: Analyzes and blocks unknown threats.

Question 56: How does Palo Alto enforce data loss prevention (DLP)?

Answer: Palo Alto enforces DLP by inspecting outbound traffic for sensitive data patterns and applying policies to block or alert on data exfiltration. DLP profiles can be configured to detect specific data types, such as credit card numbers or social security numbers, ensuring data security and compliance.

Question 57: What is the significance of content updates in Palo Alto?

Answer: Content updates provide the latest threat signatures, URL filtering categories, and application definitions. Regular updates ensure the firewall can detect and block new threats, enforce current policies, and recognize emerging applications, maintaining optimal security.

Question 58: How does Palo Alto’s Zone Protection Profile enhance security?

Answer: Zone Protection Profiles protect against network-based threats by configuring protection against floods, reconnaissance, packet-based attacks, and non-IP-protocol-based attacks. Applying these profiles to zones helps defend against various network-level attacks.

Question 59: What is the role of the Threat Prevention subscription in Palo Alto?

Answer: The Threat Prevention subscription provides advanced threat detection and prevention capabilities, including antivirus, anti-spyware, vulnerability protection, and intrusion prevention. It ensures the firewall can detect and block sophisticated threats in real-time.

Question 60: How does Palo Alto’s Panorama improve firewall management?

Answer: Panorama provides centralized management for multiple Palo Alto firewalls, offering configuration, monitoring, and reporting capabilities. It simplifies administration by allowing policy enforcement, updates, and log aggregation from a single interface, enhancing operational efficiency.

Question 61: What is the purpose of a Decryption Policy in Palo Alto?

Answer: A Decryption Policy in Palo Alto determines which SSL/TLS traffic should be decrypted and inspected. It specifies rules based on source, destination, URL category, and application, ensuring sensitive traffic is securely decrypted for threat inspection while maintaining privacy.

Question 62: How does Palo Alto’s VPN feature support remote access?

Answer: Palo Alto’s VPN feature supports remote access by allowing users to securely connect to the corporate network from remote locations. It uses IPsec or SSL/TLS protocols to encrypt traffic, ensuring secure communication between remote users and internal resources.

Question 63: What is the purpose of the AutoFocus service in Palo Alto?

Answer: AutoFocus is a threat intelligence service that provides detailed analysis and context for security events. It leverages global threat data and machine learning to help security teams understand and respond to threats, improving threat detection and incident response.

Question 64: How does Palo Alto’s GlobalProtect ensure secure mobility?

Answer: GlobalProtect ensures secure mobility by extending enterprise security policies to mobile users. It provides secure access to internal applications and enforces security policies regardless of user location, protecting mobile users from threats and ensuring compliance.

Question 65: What is a Security Profile Group in Palo Alto?

Answer: A Security Profile Group in Palo Alto bundles multiple security profiles (such as antivirus, anti-spyware, URL filtering) into a single group. This allows administrators to apply comprehensive security measures to policies easily, ensuring consistent threat protection.

Question 66: How does Palo Alto’s App-ID enhance network visibility?

Answer: App-ID enhances network visibility by accurately identifying applications, regardless of port, protocol, or encryption. It provides detailed information about application usage, allowing administrators to monitor and control traffic effectively, ensuring security and compliance.

Question 67: What is the role of the Application Command Center (ACC) in Palo Alto?

Answer: The ACC provides an interactive, graphical summary of network traffic, applications, users, and threats. It uses firewall logs to offer visibility into network activity, helping administrators identify trends, detect anomalies, and make informed security decisions.

Question 68: How does Palo Alto’s URL Filtering help enforce compliance?

Answer: URL Filtering enforces compliance by controlling access to websites based on predefined categories and custom policies. It blocks access to inappropriate or non-compliant sites, helping organizations adhere to regulatory requirements and internal policies.

Question 69: What is the function of the WildFire subscription in Palo Alto?

Answer: The WildFire subscription provides advanced malware analysis and detection capabilities. It analyzes suspicious files in a cloud-based environment, identifies new malware, and generates signatures to block threats globally, enhancing the firewall’s threat prevention capabilities.

Question 70: How does Palo Alto support IPv6?

Answer: Palo Alto supports IPv6 by providing full IPv6 traffic inspection, policy enforcement, and logging capabilities. The firewall can apply security policies to IPv6 traffic, ensuring consistent protection and visibility for both IPv4 and IPv6 networks.

Question 71: What are the different types of NAT supported by Palo Alto?

Answer: Palo Alto supports various types of NAT, including:

• Static NAT: Maps an unchanging private IP address to a public IP address.
• Dynamic IP and Port (DIPP) NAT: Translates multiple private IP addresses to a single public IP address with different ports.
• Destination NAT: Redirects traffic destined for a public IP address to a private IP address.

Question 72: How does Palo Alto’s Threat Intelligence Cloud enhance security?

Answer: The Threat Intelligence Cloud collects and analyzes threat data from global sources, providing real-time updates and insights. It enhances security by updating firewalls with the latest threat signatures and intelligence, ensuring protection against emerging threats.

Question 73: What is the role of a Security Zone in Palo Alto?

Answer: A Security Zone in Palo Alto defines a segment of the network with specific security policies. It groups interfaces and traffic for policy application, ensuring controlled and secure communication between different parts of the network.

Question 74: How does Palo Alto’s VPN feature support site-to-site connectivity?

Answer: Palo Alto’s VPN feature supports site-to-site connectivity by establishing secure tunnels between different network locations. It uses IPsec protocols to encrypt traffic, ensuring secure communication between branch offices, data centers, and remote sites.

Question 75: How does Palo Alto ensure high availability (HA)?

Answer: Palo Alto ensures high availability by using active/passive or active/active HA configurations. It synchronizes state and configuration information between firewalls, providing redundancy and failover capabilities to maintain network uptime and security.

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