Chapter 3: Using Linux and Linux Tools for Network Diagnostics
In this chapter, we'll cover some "how it works" networking basics, as well as how to use our Linux workstation in network troubleshooting. When you're done with this chapter, you should have tools to troubleshoot local and remote network services, as well as to "inventory" your network and its services.
In particular, we'll cover the following topics:
- Networking basics – the OSI model.
- Layer 2 – relating IP and MAC addresses using ARP, with some more detail on MAC addresses.
- Layer 4 – how TCP and UDP ports work, including the TCP "three-way handshake" and how this appears in Linux commands.
- Local TCP and UDP port enumeration, and how these relate to running services.
- Remote port enumeration using both native tools.
- Remote port enumeration using installed scanners (netcat and nmap in particular).
- Finally, we'll cover...