What is a firewall? Can you provide any examples of

network security device or software that controls incoming and outgoing network traffic based on security rules: 

  • Packet Filtering(ip)
  • Stateful Inspection(active connections)

• If I want to block incoming traffic on port 8080 on Linux
machine. How do I do that?

firewall tool like iptables or firewalld (sudo iptables -A INPUT -p tcp –dport 8080 -j DROP)

• What is the function of the Linux kernel?

bridge between the hardware and the software layers of a computer system

• Can you explain what LDAP is?

It’s a protocol used for accessing and managing directory information over a network(used for authentication, authorization)


• Say for example you want to run a script on a recurring day
at a certain time, can you think of any way to do this in

Tools such as cron and shell scripting. Time in editor and path

• What is OOP and what are the four basic principles?

Encapsulation, Inheritance, Polimorphism, Abstraction

• What is a class/variable/array?

A class is a template for creating objects(defines attributes and methods)

A variable is a named storage  that holds a value

Array is a collection of elements of the same data type

• What is the difference between a ‘While’ and ‘For’ loop?
While – specify a condition that is checked before each iteration of the loop

For Loop – The loop iterates over each item in the sequence until the end is reached.