Top 50 Firewall Interview Questions and Answers 2025

Firewall is a network security system that monitors and controls incoming and outgoing network traffic. VPN is a secure connection between two networks over the internet.

• Firewall acts as a barrier between a trusted internal network and untrusted external network

• It can be hardware or software-based

• It can block or allow traffic based on predefined rules

• VPN creates a secure and encrypted connection between two networks over the internet

• It allows remote access to a private networ...read more

To allow incoming traffic of a particular device to access DVR service between two subnets, we can use port forwarding and firewall rules.

• Configure port forwarding on the router to redirect traffic from a specific port to the DVR's IP address

• Create firewall rules to allow incoming traffic from the device's IP address to the DVR's IP address and port

• Ensure that the subnets are properly configured and can communicate with each other

To create firewall rules on a Checkpoint device, follow these steps:

• Log in to the Checkpoint device using SmartConsole

• Navigate to the Firewall tab and select the Access Rules section

• Click on the Add Rule button and specify the source, destination, and service for the rule

• Set the action for the rule (allow, drop, reject, etc.)

• Click on Install Policy to apply the new rule to the device

Firewall is a security system that monitors and controls incoming and outgoing network traffic. OSI is a model for network communication.

• Firewall is a hardware or software-based security system that filters network traffic based on predefined rules.

• It acts as a barrier between a trusted internal network and an untrusted external network.

• OSI (Open Systems Interconnection) is a model for network communication that defines a seven-layered approach to data transmission.

• Each layer...read more

Firewall filters network traffic based on predefined security rules, while router forwards data packets between computer networks.

• Firewall acts as a barrier between internal network and external network, filtering incoming and outgoing traffic based on security rules.

• Router forwards data packets between different computer networks, determining the best path for the packets to reach their destination.

• Firewall can block specific ports or IP addresses to prevent unauthorized acc...read more

Firewall is a security system that monitors and controls incoming and outgoing network traffic based on predetermined security rules.

• Firewall acts as a barrier between a trusted internal network and untrusted external network.

• It helps prevent unauthorized access to or from a private network.

• Firewalls can be hardware-based or software-based, and can be configured to block or allow specific traffic.

• Examples of firewalls include Cisco ASA, Palo Alto Networks, and Windows Firewal...read more

Bulk layers can be changed or filtered by adjusting the layer properties in the design software.

• Access the layer properties in the design software

• Change the visibility or order of bulk layers

• Apply filters to show or hide specific layers

• Adjust layer properties such as color, line weight, and transparency

I have extensive knowledge in Active Directory (AD) and firewall technologies.

• Experience in designing, implementing, and managing Active Directory environments

• Knowledge of group policies, user permissions, and domain controllers

• Familiarity with firewall technologies such as Cisco ASA, Palo Alto, and Fortinet

• Understanding of firewall rules, VPN configurations, and network security best practices

To set firewall outside policy, you need to adjust the rules and configurations to allow or block specific traffic.

• Review the current firewall policy to understand what is allowed and what is blocked

• Identify the specific traffic or IP addresses that need to be allowed or blocked

• Adjust the firewall rules and configurations accordingly

• Test the changes to ensure they are working as intended

LAN stands for Local Area Network. A firewall is a network security system that monitors and controls incoming and outgoing network traffic based on predetermined security rules.

• LAN is a network of interconnected devices within a limited area, such as a home, office, or campus.

• Firewall works by examining data packets and determining whether they should be allowed through based on predefined security rules.

• Firewalls can be hardware-based or software-based, and they help protec...read more

A firewall is a network security system that monitors and controls incoming and outgoing network traffic based on predetermined security rules.

• Acts as a barrier between internal network and external networks

• Filters incoming and outgoing traffic based on set rules

• Can be hardware-based or software-based

• Can block unauthorized access while allowing legitimate traffic

• Can be configured to log and report on network activity

A firewall can be used to manage network traffic and ensure smooth operation.

• Define clear security policies and rules for the firewall

• Regularly update and maintain the firewall software

• Monitor network traffic and adjust firewall settings as needed

• Implement intrusion detection and prevention systems

• Train employees on safe browsing habits and network security

• Use VPNs to secure remote access to the network

Yes, I have experience in firewall and storage.

• I have configured and managed firewalls to secure network traffic.

• I have set up and maintained storage systems to ensure data availability and integrity.

• I have experience with firewall rules, VPN configurations, and storage protocols like NFS and iSCSI.

Firewall is a network security system that monitors and controls incoming and outgoing network traffic. NAT (Network Address Translation) is a process used to modify network address information in packet headers while in transit.

• Firewall acts as a barrier between a trusted internal network and untrusted external network

• Firewall can be hardware-based or software-based

• NAT allows multiple devices on a local network to share a single public IP address

• NAT can be used to hide the i...read more

Firewall is a network security system that monitors and controls incoming and outgoing network traffic.

• Firewall acts as a barrier between a trusted internal network and untrusted external network

• It can be used to block unauthorized access to a network

• It can also be used to block outgoing traffic to prevent data leakage

• Firewalls can be hardware or software-based

• Examples of firewalls include Cisco ASA, Fortinet FortiGate, and pfSense

ACI stands for Application Centric Infrastructure, a software-defined networking solution. Firewall is a network security system that monitors and controls incoming and outgoing network traffic.

• ACI is a software-defined networking solution that provides centralized automation and policy-driven application profiles.

• ACI helps in simplifying network operations, improving security, and enabling application agility.

• Firewall is a network security system that acts as a barrier betwe...read more

A port channel is a method used to bundle multiple physical ports together to increase bandwidth and redundancy. A firewall is a network security device that monitors and controls incoming and outgoing network traffic based on predetermined security rules.

• Port channel is used to increase bandwidth and redundancy by bundling multiple physical ports together

• Firewall is a network security device that monitors and controls network traffic based on security rules

• Port channel is co...read more

A firewall filters traffic based on predetermined rules, while a next generation firewall includes additional features like intrusion prevention and application awareness.

• Firewall filters traffic based on IP addresses and ports

• Next generation firewall includes intrusion prevention, application awareness, and deep packet inspection

• NGFW can identify and block advanced threats like malware and ransomware

• NGFW can provide more granular control over applications and users

A firewall is a network security system that monitors and controls incoming and outgoing network traffic based on predetermined security rules.

• Firewalls can be hardware or software-based

• They can be configured to block or allow traffic based on IP addresses, ports, protocols, and other criteria

• Firewalls can also be used to create virtual private networks (VPNs) for secure remote access

• IP binding is the process of associating a specific IP address with a particular device or us...read more

Missileware is a type of software used in missile systems, while a filter is a program that screens data.

• Missileware is designed to control and guide missiles, while filters are used to sort and block data.

• Missileware is typically used in military applications, while filters are used in various industries such as email and internet security.

• Examples of missileware include guidance systems for missiles, while examples of filters include spam filters and content filters.

Firewall is a security system that monitors and controls incoming and outgoing network traffic, while a gateway is a node that connects two different networks.

• Firewall is a security system that filters network traffic based on predetermined security rules.

• Gateway is a node that acts as an entry and exit point for data between two networks.

• Firewall can be a software program or a hardware device, while gateway is typically a hardware device.

• Examples of firewalls include Cisco A...read more

I have extensive experience with firewalls, including configuring, monitoring, and troubleshooting issues.

• Configured firewalls to restrict unauthorized access

• Monitored firewall logs for suspicious activity

• Troubleshooted firewall issues to ensure network security

• Implemented firewall rules to comply with company policies

• Worked with vendors to resolve firewall hardware or software issues

NATting of firewall involves translating private IP addresses to public IP addresses for outgoing traffic.

• NAT (Network Address Translation) is used to hide private IP addresses behind a public IP address.

• It allows multiple devices on a local network to share a single public IP address.

• Types of NAT include Static NAT, Dynamic NAT, and PAT (Port Address Translation).

Firewall traffic flow refers to the movement of data packets through the firewall based on defined rules and policies.

• Firewall inspects incoming and outgoing traffic to determine if it should be allowed or blocked

• Traffic flow can be controlled using access control lists (ACLs) and security policies

• Firewall can also perform Network Address Translation (NAT) to hide internal IP addresses

• Examples of traffic flow include allowing HTTP traffic on port 80 while blocking FTP traffic...read more

ASA firewall packet flow involves ingress, inspection, egress, and NAT.

• Ingress: packets enter the firewall through an interface

• Inspection: packets are inspected by the firewall's security policy

• Egress: packets exit the firewall through an interface

• NAT: network address translation is applied to the packet if configured

• Example: A packet enters the firewall through the outside interface, is inspected by the access control policy, has NAT applied, and exits through the inside int...read more

Traffic inspection of checkpoint firewall involves analyzing network traffic for security purposes.

• Checkpoint firewall inspects traffic at the application layer to identify and block malicious traffic

• It uses various security mechanisms such as stateful inspection, deep packet inspection, and intrusion prevention system

• Traffic can be inspected based on source/destination IP, port, protocol, and content

• Logs are generated for all traffic events and can be analyzed for security i...read more

Firewalls are network security devices that monitor and control incoming and outgoing network traffic.

• Packet-filtering firewalls

• Proxy firewalls

• Stateful inspection firewalls

• Next-generation firewalls

• Application-level gateways

Palo Alto is called Next Generation Firewall due to its advanced security features and capabilities.

• Palo Alto offers application awareness and control, which allows it to identify and block threats that traditional firewalls cannot.

• It uses machine learning and artificial intelligence to detect and prevent advanced threats.

• Palo Alto provides visibility into network traffic and can enforce security policies based on user and device identity.

• It offers integrated threat intellige...read more

Firewall works as a barrier between internal and external networks. OSI layer is a model for network communication.

• Firewall filters incoming and outgoing traffic based on predefined rules.

• OSI layer has 7 layers: Physical, Data Link, Network, Transport, Session, Presentation, and Application.

• Each layer has its own set of protocols and functions.

• Firewalls operate at the network and transport layers of the OSI model.

• Firewalls can be hardware or software-based.

• OSI layer helps in ...read more

Firewall filters traffic based on security rules, while router forwards data packets between networks.

• Firewall is used to block or allow traffic based on security rules, while router is used to forward data packets between networks

• Firewall operates at the network layer (Layer 3) or above, while router operates at the network layer (Layer 3)

• Firewall can inspect and filter traffic based on IP addresses, ports, protocols, and application types, while router primarily forwards pa...read more

Packet flow in Fortigate device involves ingress, inspection, decision making, and egress stages.

• Ingress stage: packets enter the Fortigate device through interfaces

• Inspection stage: packets are inspected based on security policies and rules

• Decision making stage: Fortigate device determines actions to take on packets (allow, deny, etc.)

• Egress stage: packets exit the Fortigate device through interfaces

Firewalls are used to protect networks from unauthorized access and have features like packet filtering, NAT, VPN, and IDS/IPS.

• Firewalls prevent unauthorized access to a network by filtering incoming and outgoing traffic based on predefined rules.

• They can also perform Network Address Translation (NAT) to hide the internal IP addresses from external networks.

• Firewalls can establish Virtual Private Networks (VPNs) to securely connect remote users or sites to the network.

• They ca...read more

Cisco ASA Firewall uses failover to ensure high availability and uninterrupted network services.

• Failover is the process of switching to a backup device in case of a failure in the primary device.

• Cisco ASA Firewall supports two types of failover: Active/Standby and Active/Active.

• In Active/Standby failover, one firewall is active and the other is in standby mode, ready to take over in case of a failure.

• In Active/Active failover, both firewalls are active and share the traffic l...read more

Firewall works on multiple layers of OSI model

• Firewall operates on layers 3 (network layer) and 4 (transport layer) of the OSI model

• It can filter traffic based on IP addresses, ports, protocols, and other criteria

• Firewalls can also perform deep packet inspection to detect and block malicious traffic

• Examples of firewall software include Cisco ASA, pfSense, and Windows Firewall

Application level firewall filters traffic based on application layer protocols while stateful firewall filters based on connection state.

• Application level firewall operates at layer 7 of OSI model while stateful firewall operates at layer 4.

• Application level firewall can block specific applications while stateful firewall cannot.

• Stateful firewall keeps track of connection state while application level firewall does not.

• Examples of application level firewall include proxy ser...read more

Firewalls are network security systems that monitor and control incoming and outgoing network traffic.

• Firewalls can be hardware or software-based

• They can be configured to block or allow specific types of traffic

• Firewalls can prevent unauthorized access to a network

• They can also be used to monitor network activity and detect potential threats

• Examples of popular firewall software include Norton, McAfee, and Windows Firewall

Firewall is a network security system that monitors and controls incoming and outgoing network traffic based on predetermined security rules.

• Firewall acts as a barrier between a trusted internal network and untrusted external network

• It can prevent unauthorized access to a network

• It can block malicious traffic and prevent malware from entering the network

• It can also be used to restrict access to certain websites or applications

• Examples of firewalls include hardware firewalls, ...read more

VLAN is a logical grouping of devices on a network while DMZ is a network segment that separates an organization's internal network from an untrusted external network.

• VLAN stands for Virtual Local Area Network and is used to group devices together based on their function or location

• DMZ stands for Demilitarized Zone and is a network segment that separates an organization's internal network from an untrusted external network

• DMZ is typically used to host servers that need to be ...read more

A firewall is a network security system that monitors and controls incoming and outgoing network traffic based on predetermined security rules.

• Firewalls can be hardware or software-based

• They can be configured to block or allow traffic based on IP addresses, ports, protocols, and other criteria

• Firewalls can be used to protect against unauthorized access, malware, and other security threats

• Examples of popular firewall solutions include Cisco ASA, Fortinet FortiGate, and Palo Al...read more

Firewalls are network security systems that monitor and control incoming and outgoing network traffic based on predetermined security rules.

• Types of firewalls include packet filtering firewalls, stateful inspection firewalls, proxy firewalls, and next-generation firewalls.

• Packet filtering firewalls examine packets of data and decide whether to forward or discard them based on predetermined criteria.

• Stateful inspection firewalls keep track of the state of active connections an...read more

Firewalls are used to protect networks by controlling incoming and outgoing network traffic.

• Firewalls act as a barrier between a trusted internal network and untrusted external networks.

• They monitor and filter network traffic based on predetermined security rules.

• Firewalls can prevent unauthorized access to a network, block malicious traffic, and protect against cyber attacks.

• Examples of firewalls include hardware firewalls, software firewalls, and cloud-based firewalls.

Stateful firewall tracks the state of active connections, while stateless firewall filters packets based on predetermined rules.

• Stateful firewall maintains a state table to track the state of active connections, allowing it to make more informed decisions on which packets to allow or block.

• Stateless firewall filters packets based on predetermined rules such as source/destination IP addresses, ports, and protocols without considering the state of the connection.

• Stateful firewa...read more

Firewall security is a network security system that monitors and controls incoming and outgoing network traffic based on predetermined security rules.

• Acts as a barrier between a trusted internal network and untrusted external network

• Filters network traffic based on set rules to prevent unauthorized access

• Can be hardware-based or software-based

• Examples include Cisco ASA, Palo Alto Networks, and Windows Firewall

Firewalls are network security systems that monitor and control incoming and outgoing network traffic based on predetermined security rules.

• Firewalls act as a barrier between a trusted internal network and untrusted external networks.

• They can be hardware-based or software-based.

• Firewalls can filter traffic based on IP addresses, port numbers, protocols, and application types.

• Examples of firewalls include packet-filtering firewalls, proxy firewalls, and next-generation firewal...read more

Securing a firewall involves configuring access control, implementing intrusion detection systems, and regularly updating security policies.

• Configure access control lists to allow only necessary traffic

• Implement intrusion detection systems to monitor for suspicious activity

• Regularly update firewall rules and security policies to address new threats

• Enable logging and monitoring to track firewall activity

• Use strong authentication methods for accessing the firewall

• Regularly revi...read more

Stateless firewall filters packets based solely on the information in the packet header, while stateful firewall keeps track of the state of active connections.

• Stateless firewall operates at the network layer and filters packets based on IP addresses and ports

• Stateful firewall operates at the session layer and keeps track of the state of active connections

• Stateful firewall can make decisions based on the context of the traffic, such as whether a packet is part of an establish...read more

I would troubleshoot the issue by checking the logs, verifying the policy rules, and ensuring proper configuration.

• Check the logs to identify the specific error or issue

• Verify the policy rules to ensure they are correctly configured

• Check for any conflicts or overlapping rules that may be causing the failure

• Ensure that the policy installation process was completed successfully

• Consult with colleagues or documentation for troubleshooting steps

There are four types of logs in the monitor tab in Panorama.

• Traffic logs

• Threat logs

• URL logs

• Data logs

Firewall security is necessary to protect computer networks from unauthorized access and malicious attacks.

• Prevents unauthorized access to a network

• Filters incoming and outgoing network traffic

• Blocks malicious traffic and viruses

• Enforces network security policies

• Logs network activity for auditing and analysis

Check the system logs for cluster failure in Paloalto firewall.

• Check the system logs for any error messages related to cluster failure

• Look for logs indicating cluster synchronization issues

• Review logs for any hardware or software failures in the cluster

Leading firewalls in the market include Palo Alto Networks, Cisco Firepower, and Fortinet. Each has its own speciality in terms of features and capabilities.

• Palo Alto Networks: Known for its advanced threat prevention capabilities and integration with cloud services.

• Cisco Firepower: Offers a combination of firewall and intrusion prevention system (IPS) for comprehensive security.

• Fortinet: Specializes in providing high-performance security solutions with features like sandboxi...read more

Firewalls are network security systems that monitor and control incoming and outgoing network traffic.

• Firewalls can be hardware, software, or cloud-based.

• Types of firewalls include packet-filtering, stateful inspection, proxy, and next-generation firewalls.

• Packet-filtering firewalls examine packets and filter them based on pre-defined rules.

• Stateful inspection firewalls keep track of the state of network connections and filter traffic based on that information.

• Proxy firewalls...read more

Firewall is a network security system that monitors and controls incoming and outgoing network traffic based on predetermined security rules.

• Firewalls can prevent unauthorized access to a network or computer system

• They can block malicious traffic from entering the network

• Firewalls can be hardware-based or software-based

• Examples of firewalls include Cisco ASA, Palo Alto Networks, and Windows Firewall

VDOM is a virtual domain feature in Fortigate Firewall that allows multiple virtual firewalls to be created on a single physical device.

• VDOM provides separate security policies, interfaces, routing tables, and administrators for each virtual firewall.

• It helps in reducing hardware costs and simplifying network management.

• Each VDOM has its own set of interfaces, security policies, routing tables, and administrators.

• VDOMs can be used to create separate virtual firewalls for diff...read more

Firewalls are network security systems that monitor and control incoming and outgoing network traffic.

• Firewalls can be hardware or software-based

• They can be configured to block or allow specific traffic based on rules

• Firewalls can prevent unauthorized access to a network

• They can also be used to block malicious traffic and prevent attacks

• Examples of firewalls include Cisco ASA, Fortinet FortiGate, and pfSense

NGFw stands for Next-Generation Firewall and it has advanced features compared to traditional firewalls.

• NGFw can identify and block advanced threats like malware, ransomware, and phishing attacks.

• It can perform deep packet inspection to analyze network traffic and detect anomalies.

• NGFw can also provide application-level visibility and control to manage network traffic based on application usage.

• It can integrate with other security solutions like SIEM and threat intelligence p...read more

Sophos firewall is a network security solution that provides protection against various cyber threats.

• Sophos firewall is based on a unified threat management (UTM) platform

• It offers features such as intrusion prevention, web filtering, and application control

• Sophos firewall also includes advanced threat protection capabilities like sandboxing and machine learning

• It can be deployed on-premises or in the cloud

• Sophos firewall integrates with other Sophos security products for a ...read more

FortiGate firewall packet flow

• Incoming packet is received by the FortiGate interface

• Packet is checked against security policies

• If allowed, packet is forwarded to the appropriate destination

• If denied, packet is dropped or rejected

• Outgoing packet is processed in reverse order

Stateful firewall keeps track of the state of active connections and makes decisions based on the context of the traffic.

• Stateful firewall inspects incoming and outgoing packets and compares them to a database of trusted connections.

• It allows or blocks traffic based on the state of the connection and predefined rules.

• Examples include Cisco ASA, Palo Alto Networks, and Fortinet firewalls.

Firewalls are network security devices that monitor and control incoming and outgoing network traffic.

• Firewalls act as a barrier between internal and external networks, filtering traffic based on predefined rules.

• They can be hardware or software-based, and can be configured to allow or block specific types of traffic.

• Firewalls can protect against unauthorized access, malware, and other network threats.

• Examples of firewalls include Cisco ASA, Palo Alto Networks, and pfSense.

Firewall architecture involves packet filtering, stateful inspection, and application layer filtering to protect networks.

• Firewall acts as a barrier between internal network and external network

• Packet filtering examines packets based on predefined rules to allow or block traffic

• Stateful inspection tracks the state of active connections to make decisions on allowing or blocking traffic

• Application layer filtering inspects data at the application layer to block malicious content...read more

Site-to-Site VPN on Palo Alto firewalls allows secure communication between different sites.

• Configure VPN tunnel interface on both firewalls

• Define IKE gateway and IPsec crypto profile

• Create VPN tunnel interface and assign IP address

• Define security policies to allow traffic through the VPN tunnel

Firewall is a network security system that monitors and controls incoming and outgoing network traffic based on predetermined security rules.

• Firewall acts as a barrier between a trusted internal network and untrusted external network.

• It can block or allow traffic based on predefined rules such as IP address, port number, protocol, etc.

• Firewalls can be hardware-based or software-based, and can be configured to filter traffic at the network or application layer.

• Examples of fire...read more

Firewall is a network security system that monitors and controls incoming and outgoing network traffic based on predetermined security rules.

• Acts as a barrier between internal network and external networks

• Filters and blocks unauthorized access to the network

• Helps prevent cyber attacks and data breaches

• Can be hardware-based or software-based

• Examples: Cisco ASA, Palo Alto Networks, pfSense