For years I’ve used ncdu a NCurses Disk Usage utility for Linux. Recently someone alerted me to some other options as well as ncdu:
du + rust = dust. Like du but more intuitive, Dust is meant to give you an instant overview of which directories are using disk space without requiring sort or head. Dust will print a maximum of 1 ‘Did not have permissions message’. Dust will list the 20 biggest sub directories or files and will smartly recurse down the tree to find the larger ones. There is no need for a ‘-d’ flag or a ‘-h’ flag. The largest sub directory will have its size shown in red.
The Tin Summer:
sn is a replacement for du. It has nicer output, saner commands and defaults, and it even runs faster on big directories thanks to multithreading.
Ncdu is a disk usage analyzer with an ncurses interface. It is designed to find space hogs on a remote server where you don’t have an entire graphical setup available, but it is a useful tool even on regular desktop systems. Ncdu aims to be fast, simple and easy to use, and should be able to run in any minimal POSIX-like environment with ncurses installed.
Install from repos: sudo apt install ncdu
man page: https://dev.yorhel.nl/ncdu/man
tcpdump101.com is a great site that you can use to generate tcpdump commands, you enter the parameters it’s asks for and it will generate the command for you. It’s handy if you are not running tcpdump commands very often and then have to either look up the help/man pages or Google for the command switches you want. It also has output for Cisco and Checkpoint firewalls.
From there site they say… tcpdump101.com has been designed to help people capture packets on different devices to assist with network troubleshooting, service troubleshooting and even passive red team activities. There is an assumption that the user has a basic understanding of what they want to capture – As much as this is a tool to help people, the user has to use their own logic since every situation is different. That being said, I strongly suggest that if you’re just starting out with packet captures to grab a copy of Virtual Box and play around with Linux and tcpdump. Although tcpdump may not be what you ultimately use, it will give you an excellent understanding of what you’ll see, even with other products and vendors.
As a safety measure (if at all possible) make sure to set a capture limit on your PCaps. If you make a mistake building your filters, you may end up captuing a lot of traffic. Although the odds are slim, there is a chance that your PCap could fill the NIC buffer and start dropping packets. The worst-case scenario is that it runs out of memory while you’re logged in remotely. With today’s hardware, it most likely won’t happen however you should always expect the best and plan for the worst.