Taking notes on the course of of Practical Ethical hacking. This is just a blog post going over the first few sessions.

Notekeeping is super important!
Make sure that you have a good notekeeping application and some good notekeeping habits. Screenshots and organizations are nice and they speed things up. He made the point that sometimes clients will come back 6 months later and they want to know what you did at what time. Keepnote is the application that he uses. Cherrytree, OneNote, and Joplin. ( I have started to use keepnote as it is a simple program ) Flameshot runs great on arch as well.

Networking - the classic foundational skill.
IP addresses are made up of 8 bytes and there are four quartets of these 8 bytes. Within each section, there are 0-255 possible values. There are 4 billion possible ipv4 addresses. IPv6 was introduced to solve this problem, but as they are non-human friendly addresses people tended to stay with IPv4 and use NAT. NAT is a solution for extending multiple IP addresses.

Remember that there are different types of networks broken up to server different shapes of networks.

Net. Numbers Net. Mask No. of Networks No. Hosts  
Class A network 10.0.0.0 255.0.0.0 126 ~16,000,000
Class B network 172.16-31.0.0 255.255.0.0 ~16,000 ~65,000
Class C network 192.168.0-255.0-255 255.255.255.0 ~2,000,000 ~254

Heath has also provided the greatest memonic for the OSI stack:

# phrase layer example
1 Please Physical data cables, cat6
2 Do Switching MAC addreses
3 Not Networking Ip addresses, routing
4 Throw Transport TCP/UDP
5 Sausage Session Session managment
6 Pizza Presentation WMV
7 Away Application HTTP, SMTP

MAC Addresses - media access control or burned in address. Physical address that is tied to the manufacturer. Layer 2.

TCP and UDP TCP - transmission control protocol. Connection oriented. FTP HTTP and HTTPS. Utilizes a three way handshake UDP - user datagram protocol. Stream orientated. Video, dns, and VOIP.

The common ports SMB 139 + 445 the classic ports. Wannacry and Eternal Blue. See this a lot out in the wild.

Then, TCM goes through a great overview of subnetting including a very good chart. Having taken Keith Barker’s course on youtube, I would recommend using a mixture of both of these methods. Subnetting just took repetition for me to really understand it. If you also take the time to work out the problems with a pen and paper that helps as well. Following that there is a discussion on how to get VMs set-up on your machine. But, hey, we use arch here so no need for that.

(I also figured out tables in markdown)