• Bus – simple but vulnerable
• Ring – simple, vulnerability can be handled by concentric design
• Star – most common, resistance to outages, node failure does not cause the whole network to go down
• Mesh – for mission critical services, high level of redundancy; Internet
• Hybrid – mix of the above

Everyone has its own, but it usually consists of:

• Footprinting (passive)
• Scanning (active)
• Enumeration – is there a value behind the door?
• Hacking – attack execution
• Covering – hiding the activity from previous steps
• Backdoors – wanna come back?

We do not refer to the Central Intelligence Agency but key concepts in ethical hacking:

• Confidentiality – keep the information away from non-authorized people/systems; using encryption, access rights
• Integrity – keep the information unaltered by non-authorized
• Availability – keep the information available to those who need it

Opposite would be:

• Disclosure
• Alteration
• Disruption

Hacker’s needs to commit a crime are the same like in case of a regular crime:

• Means
• Motive
• Opportunity

Ethical Hacker’s needs:

• Good contract
• Do only what you have permission to do
• Confidentiality and privacy in mind

Get the current session type, text-mode or graphical:

systemctl get-default

Set the current session type to text-mode by disabling gdm autostart:

systemctl set-default multi-user.target

Enable lightdm autostart:

systemctl set-default graphical.target