20 Daily Linux Commands System Administrators Use in Production

 While Linux offers thousands of commands, not all of them are part of your day-to-day toolbox. However, there’s a core set of powerful, reliable commands that you’ll find yourself using every single day, often multiple times.

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Did you know

 

DNS Troubleshooting Infographic

 

Wireshark and Passive Network Discovery

 

Someone asked me if you can use Wireshark to discover devices.

The answer is kind of no in the sense that Wireshark doesn’t actively go out and ping or scan your network to find hosts.  But you can use Wireshark to listen or ‘passively’ discover devices on your network.

As always, I will keep it short and just say that everything you need to know is in the video.

Capture Packets Using Python And Pyshark Using Less Than 5 Lines Of Code

 

Now for something completely different…

I think network professionals should be ‘aware’ of coding.  Not necessarily a programmer, but at least be familiar with what can be done.

So I thought why not combine 2 of my favorite things; python and capturing packets.

All you have to do is install python, where you can get from https://www.python.org . Then go to the command prompt and type the following command

pip install pyshark

Use your favorite text editor and create a text file with the extension py and enter the following text.

import pyshark

capture = pyshark.LiveCapture(interface='eth0')

capture.sniff(timeout=1)

capture

The code is supposed to capture packets for 1 second and stop, but the real purpose of this program is to cause an error so I can get a list of interfaces.  I know its crude, but its effective.

Type python program.py

Find the line that describes your network interface and copy the text above it.

For example, here is the output from my script ,

\Device\NPF_{82C048B7-BF6D-4B92-BDFA-872CFC8F7077}

Killer

You need to put \\Device\\NPF_{82C048B7-BF6D-4B92-BDFA-872CFC8F7077}

In my script and make sure you have 2 \\’s

Here is my new code that will capture 100 packets and save it in a test.pcapng

import pyshark

capture = pyshark.LiveCapture(interface='\\Device\\NPF_{82C048B7-BF6D-4B92-BDFA-872CFC8F7077}',output_file='./test.pcapng')

# capture for 5 seconds and stop

# capture.sniff(timeout=5)

#capture 100 packets and stop

capture.sniff(packet_count=100)

capture

Have fun you future coders  😉