added Nessus

Software/Nessus.md

@@ -0,0 +1,86 @@
+---
+Classes:
+  - Networking for Cybersecurity
+---
+
+# Nessus
+Nessus is a proprietary vulnerability scanner.
+
+## Download
+Nessus can be downloaded from https://www.tenable.com/downloads/nessus
+
+### Arch-Based
+No need to download from the website, skip to [Install](#install)
+
+### Debian
+Select "**Linux - Debian - amd64**" to download.
+
+### Fedora
+Select "***Linux - Fedora - x86_64**" to download.
+
+### Mint/Ubuntu 
+Select "**Linux - Ubuntu - amd64**" to download.
+
+## Install
+
+### Arch-Based (AUR Package)
+```sh
+yay -S nessus
+```
+
+### Debian
+Replace `<version-number>` with the version number in the file name
+```sh
+sudo dpkg -i ~/Downloads/Nessus-<version number>-debian6_amd64.deb
+```
+
+Note: By default it will be set to start every boot, to disable that run:
+```sh
+sudo systemctl disable nessusd
+```
+You will still be able to run it as normal.
+
+### Fedora
+Replace `<version-number>` with the version number in the file name
+```sh
+sudo dnf install ~/Downloads/Nessus-<version number>-fc38.x86_64.rpm
+```
+
+### Mint/Ubuntu
+Replace `<version-number>` with the version number in the file name
+```sh
+sudo dpkg -i ~/Downloads/Nessus-<version number>-ubuntu_amd64.deb
+```
+
+Note: By default it will be set to start every boot, to disable that run:
+```sh
+sudo systemctl disable nessusd
+```
+You will still be able to run it as normal.
+
+### Podman (Universal)
+Podman is a container system very similar to docker that lets you run programs in an isolated and self-contained environment. Tenable provides a Nessus container that will let you run Nessus on any linux system.
+
+First install [Podman](../Tools/Podman.md) on your computer.
+
+The container image will automatically be downloaded when you run nessus with:
+```sh
+podman run -p 8834:8834 docker.io/tenable/nessus:latest-ubuntu
+```
+
+## Usage
+### Start (Normal)
+```sh
+sudo systemctl start nessusd
+```
+
+### Start (Podman)
+The command in the install section is the same command to run it, simply leave the console window open. If you wish to run it in the background add the `-d` (detach) flag like so:
+```sh
+podman run -d -p 8834:8834 docker.io/tenable/nessus:latest-ubuntu
+```
+
+See the document on [Podman](../Tools/Podman.md) to learn how to control a container running in the background.
+
+### Access
+You should now be able to access it on https://localhost:8834/