====== System administrator interview questions ======

===== Linux =====
see [[:guide:linux:interview]]

===== Databases =====
  - discuss the steps you would take to secure a [MySQL/PostgreSQL/MS SQL] installation, including best practices for setting up user accounts, implementing encryption, and configuring firewalls?
  - how do you prevent lateral movement of a hacker who successfully attacked one of your database applications?

===== Firewall =====
  - How does firewalld work on CentOS systems and which file format do the rulesets have?
  - What is UFW on Debian?
  - What is the difference between nftables and iptables?
  - What is the role of systemd network namespaces?

===== Mail =====
  - Can you explain how DKIM works in email security and how it can be used to prevent email spoofing and fraud?
    - What are the steps for setting up DKIM for a domain and how does it interact with other email security technologies?

===== TLS Certificates =====
  - How does the ACME DNS challenge work in the process of obtaining SSL/TLS certificates from a certificate authority?
    - What are the benefits and limitations of using this challenge method?

===== Encryption =====
  - What is the purpose of using GPG subkeys and how can they be used to enhance the security of GPG encryption?

===== VPN =====
  - How does the IPSec protocol ensure secure and encrypted communication between two or more endpoints, and what are the differences between transport mode and tunnel mode?
  - What are differences and use cases for OpenVPN and IPSec VPN?
    - what are the benefits and challenges of each solution in terms of scalability, security, and compatibility?