Welcome to some great networking and computing tips.
Usually these have to do with how to do this or how to change that. The subjects are fairly broad when it comes to networking and we encourage both your feedback and contributions by adding comments and extending any of the tips. If there is something you need help on or something you would like to see added here, just drop us a line from the “Contact Us” link and we will be glad to try and help.
Be careful, not all tips work on all networking equipment nor operating systems. Also be sure to add your comments as well as read comments and questions from other readers.
You can click on the column titles to sort on the column information (for instance click on Hits to sort the articles in ascending frequency, click it again to sort in descending frequency). You can also select tags in the tag cloud to quickly list all articles on that particular subject.
Introduced in version 3.6 and later is a new Wireshark expert analysis process called TCP Completeness. At first this was quite confusing, but once you get to know what is going on, you come to understand that you can use this new feature to find certain types of TCP issues. We included this is our …
Zero-to-Hero – Wireshark TCP Conversation Completeness Read More »
Who is on my network? Great question. Better yet: Who is on my customer’s network? That would be looking at the issue from a service provider’s perspective. This article attempts to answer that question with tips and tricks and tools that will help you, whether you are the owner of a network or a service provider. …
When you first start using Wireshark you will find that the great folks at Wireshark provide us with a “Default” profile. This is where we all started. We will call this our Zero starting point. Here is what it looks like: That default, whilst a great starting point leaves much to be desired as your …
If you have been to one of my Wireshark or Wi-Fi classes then you know I often criticize Microsoft Windows for some of its – well – inexplicable approaches to usage and security. Here is yet another example. Let’s say someone has a Rubber Ducky, or some Arduino device, that they want to plug into …
Find and Display All Your Wi-Fi Passwords in Windows Read More »
Scenario Let’s say you have a DHCP server running on a Cisco Switch that is behaving strangely and you want to examine the traffic over a couple of hours while not creating a gigantic unmanageable capture file. A note here: I am doing this on a Cisco switch, but most all vendor switches support this …
Troubleshooting Your Network Using Port Mirroring and Packet Capture Read More »
In this article, I wanted to provide a guide to using ping – ICMP Echo – to troubleshoot your network. Most people use ping on their platform to test if they can reach a given destination. Just open up a terminal (Linux or MAC OSx) or command line (Windows: Start> Run> cmd) and enter the …
Troubleshooting The Internet Using Ping (a.k.a. ICMP) Read More »
In a recent class I was asked for some details on BGP Autonomous System (AS or ASN) Numbers. I thought I would document and provide a more complete answer here for others to learn from as well. What is the AS Number? Let’s begin with a definition. An Autonomous System Number (AS number or simply …
In this article I want to visit a “not used enough” Linux tool called logger. As with managing any system, you want to accurately annotate historical events and adding entries into the system log file is a great way to accomplish this. You can view the system log file with this command: awalding@aw-vb:~$ cat /var/log/syslog …
Too many people shrug off Linux for fears of security with a free and open source operating system, even today. For those of us who know that Linux is no less or more secure than any other operating system, we must be sensitive to this and we must be well versed in Linux commands that …
Linux Security Focused Commands We All Need to Use Read More »
Hello my Networking and IPv6 researchers and enthusiasts. I just started a PCAP repository at Github for IPv6 Extension Header (EH) packet capture examples. Honestly I found nothing worthwhile on the web, that’s not to say they don’t exists in some niche place, but I wanted something easy to access and easy to add content …
An essential function when administering a Linux system is configuring and managing users and groups. I cover adding users in this article: https://www.cellstream.com/reference-reading/tipsandtricks/582-using-the-useradd-command-to-create-user-accounts-in-linux That said, viewing users is done using a few simple commands. How To View Users on a Linux System Every user on a Linux system, whether created as an account for a real …
Like most operating systems, Linux can have multiple user accounts. The system administrator or root account, or users with sudo privileges are responsible for managing these users, as well as managing those accounts. Linux is a multi-user system, which means that more than one person can interact with the same system at the same time. …
Using the useradd Command to Create User Accounts in Linux Read More »
Hi everyone! Happy Thanksgiving 2021. Just released – Wireshark 3.6.0!!! Why is this important to me, you, and everyone who troubleshoots Voice traffic using Wireshark? Well, there are many changes to the voice related functionality in Wireshark in this (actually as part of the 3.5.0) release. Of course, more than VoIP was updated in these …
Important Updates to Wireshark for Voice and VoIP Read More »
Hi Everyone! If you are like me, you use Wireshark every day. For me that means troubleshooting many different network situations, including Voice traffic – VoIP. Wireshark announced some significant changes coming to the Voice capabilities set within Wireshark, and I hope you are like me – extremely excited to see these. If you want …
Wireshark 3.5 Development Release adds significant voice upgrades Read More »
Here is a quick and clever technique in Wireshark. Let’s say you want to present, testify, or teach about a packet capture in Wireshark, but you want to redact information that is not important, perhaps hiding an error that was made, or some information that is private, or some other reason. Redaction is often done …
