Sure! One frequently asked firewall interview question is – “Can you explain the difference between stateful and stateless firewalls, and provide examples of each?

Frequently Asked Firewall Interview Question:

One common question in firewall interviews is about the difference between stateful and stateless firewalls, along with examples of each.

Stateful Firewall:

A stateful firewall is a type of firewall that keeps track of the state of active connections and is able to make decisions based on the context of traffic. It can inspect the context of packets and determine whether they are part of an established connection or not, providing more advanced filtering capabilities.

Example: Cisco ASA (Adaptive Security Appliance) is a well-known stateful firewall that offers advanced security features such as application-layer filtering and VPN support.

Stateless Firewall:

A stateless firewall, on the other hand, filters packets based solely on predefined rules and criteria without considering the context or state of the connection. It does not maintain any information about the state of connections, making it less secure but faster in processing packets.

Example: iptables, a commonly used firewall in Linux systems, operates as a stateless packet filtering firewall, allowing or blocking traffic based on static rules defined by the administrator.

Understanding the differences between stateful and stateless firewalls, as well as knowing when to use each type based on security needs and performance requirements, is crucial for firewall administrators and network security professionals.