Welcome to our vibrant hub for all things networking and computing! At CellStream, we believe in empowering you with the knowledge to master your digital world. Whether you’re a beginner looking for foundational advice or a tech-savvy enthusiast seeking advanced techniques, our Computing Tips section is your go-to destination.
If there is something you need help on or something you would like to see added here, just drop us a line at our Discord server and we will be glad to try and help.
Be careful, not all tips work on all networking equipment nor operating systems.
Check out these great references as well: Our custom profiles repository for Wireshark Our Udemy course on Wireshark Our Udemy course on Wireless Packet capture Just introduced this week is a terminal version of tshark that looks like the Wireshark GUI call termshark. Why? Let’s say you run either Virtual Machines or Servers without a […]
A Terminal Version of tshark – we love it! Read More »
We started to notice QUIC back in 2017. For an overview of QUIC you can see my article here: https://www.cellstream.com/2018/03/07/is-there-a-lot-of-quic-in-your-packet-captures/ How do you know if a given web site uses QUIC/gQUIC? It is a great question, and can be easily answered if you are using Google Chrome (which, by now you should be!). First, you
How To Observe if the Web Site you are Browsing Uses QUIC Read More »
Check out these great references as well: Our Wireless custom profile for Wireshark Our Udemy course on Wireless Packet capture Our other Wi-Fi related articles If you are like me, you count on the Internet to help with how to’s especially when using Linux. That said, sometimes the information can be contradicting or confusing. This
3 Ways to put your Wi-Fi Interface in Monitor Mode in Linux Read More »
Check out these great references as well: Our Wireless custom profile for Wireshark Our Udemy course on Wireless Packet capture Our other Wi-Fi related articles In our article on putting your WLAN Wi-Fi interface into Monitor Mode so you can sniff Wi-Fi packets and troubleshoot WLAN’s, we said that if you are running Windows, you
Getting a Virtual Machine to Access Wi-Fi Monitor Mode Read More »
Check out these additional IPv6 Resources: Our IPv6 overview course at Udemy Our IPv6 Custom Profiles for Wireshark Our IPv6 classes at the Online School A major change in the behavior of IP networks between IPv4 and IPv6 is that in IPv6 networks, all hosts are required to support something called Path MTU (PMTU) discovery.
IPv4/IPv6 Path MTU (PMTU) Discovery Demystified Read More »
I received a question on how to create a delay to a subnet using GNS3. Below is my answer:
Creating Delay to a Subnet Tech Tip Read More »
I recently watched a YouTube video where one of the GNS3 creators was talking about GNS3 and how it runs. This convinced me to consider moving my GNS3 development work to the Linux world. I had done this years ago for the hands on training classes but my own development environment has been Windows based.
GNS3 in Linux – Tech Tip – Docker Error Read More »
One way to examine your network configuration in Linux is to use the “ip” command. I have attached a cheat sheet from Red Hat. By itself, it will show its options: So much going on here, and I find the help and man pages to be light on clarity and examples. So let’s explore.
The Linux ‘ip’ Command in Networking Read More »
Equal-Cost Multi-Path (ECMP) is a forwarding mechanism for routing packets along multiple paths of equal cost with the goal to achieve almost equally distributed link load sharing. This, of course, significantly impacts a router’s next-hop (path) decision. For further details, look at RFC 2991, “Multipath Issues in Unicast and Multicast Next-Hop Selection,” and RFC 2992,
Detecting ECMP in Linux using Paris and Dublin Traceroute Read More »
My recent blog post regarding Linux being the operating system of choice if you are supporting/testing/operating a network has spawned some great discussion. Emerging the discussion has come a request to write up a starting point list of commands for Linux beginners. I said “Sure, I can do that!” I thought it would be simple
Linux Starting Point – Commands You Need To Know Read More »
The ‘cat’ [short for “concatenate“] command is one of the most frequently used commands in Linux and other operating systems. The cat command allows us to create single or multiple files, view contain of file, concatenate files and redirect output to the terminal or to files. The command is available in Linux, Windows Power Shell, and MAC-OS.
What is the ‘cat’ command, and how can I use it? Read More »
Check out these additional IPv6 Resources: Our IPv6 overview course at Udemy Our IPv6 Custom Profiles for Wireshark Our IPv6 classes at the Online School Is there a simple way to display all the IPv6 settings on a Linux machine? Absolutely! I have done the following on Debian/Ubuntu Linux. For the newbies most system settings
IPv6 Settings (SYSCTL) on Linux Read More »
Check out these great references as well: Our custom profiles repository for Wireshark Our Udemy course on Wireshark Our Udemy course on Wireless Packet capture A great question and problem. The fundamental answer is you can’t. Why? Depends on who you believe. My conclusion is that Wireshark (really dumpcap) has to use either Npcap or
Using Wireshark to capture between VirtualBox VM’s Read More »
In our previous articles on nmap ( Getting Started with nmap and Deeper Scanning with nmap and Even Deeper Scanning with nmap and Advanced nmap Scripting Engine) we ran everything from the command line interface of various Linux distributions. When you install nmap, you also get something called ‘Zenmap’ which is the graphical user interface front end
Zenmap – the nmap GUI Read More »
In this article we continue our nmap series (just click on the nmap tag at the bottom of the article to see the other articles), this time we discuss an advanced nmap feature called the NSE: nmap Scripting Engine. This post get’s you started with nmap scripts. Once you get this, we have a complete
Advanced nmap – the nmap Scripting Engine (NSE) Read More »