Post Views: 3,906 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 […]
BGP Autonomous System (AS) Numbers Read More »
Post Views: 2,552 OK – so this article is for entertainment of all us network nerds. As many already know, pretty much every year, the Internet Engineering Task Force (IETF) releases humorous RFC’s – jokes. Usually these happen on or about April 1st to commemorate April Fools Day. Without doubt, some of these are
Humorous and April Fools Day RFC’s Read More »
Post Views: 1,177 Got to thinking the other day. What are the world’s most important RFC’s (Request for Comment specifications)? I decided to make a list. While the following are not in any order, I tried to base them (mostly) on date. While TCP came first, I still put the Internet Protocol on the top
The World’s (Generally) Most Important RFC’s of the Internet Read More »
Post Views: 8,465 In this article we will get you started with the iPerf tool. We will be using it in a Linux environment, but know that it is available for all systems at http://iperf.fr. iPerf is used to test performance, throughput, packet loss, and jitter on TCP/IP networks. iPerf defaults to testing TCP – port
Getting started with iPerf – an illustrated step by step procedure Read More »
Post Views: 1,358 CellStream, Inc. – Telecom Consulting and Training! 1-Day Instructor Led Hands On Lab Class Available in either Web Based delivery or On-Site Delivery Minimum 8 students – Maximum 16 students Course Description: Ethernet was invented as a Local Area Network protocol that busted the ceiling
CSI-HO-009-A – L2 Ethernet in a Day – 1 Day Read More »
Post Views: 2,820 Using Wireshark in Microsoft Windows reveals some quirks that naturally leave you scratching your head as to what is going on. For example, when I launch Wireshark on my Windows 10 system I see a bunch of different interfaces. Some make sense (Wi-Fi, Ethernet 2) but others….: What are all the Local
What are all the Microsoft local area connections? Read More »
Post Views: 2,462 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
A Terminal Version of tshark – we love it! Read More »
Post Views: 5,066 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.
The Linux ‘ip’ Command in Networking Read More »
Post Views: 5,181 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,”
Detecting ECMP in Linux using Paris and Dublin Traceroute Read More »
Post Views: 1,385 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
Linux Starting Point – Commands You Need To Know Read More »
Post Views: 5,282 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
Using Wireshark to capture between VirtualBox VM’s Read More »
Post Views: 1,608 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 Teaching a Wireshark class with some cellular company employees, I was asked how to integrate the GeoIP IP Address resolution. I had not done this for years,
GeoIP Add In for Wireshark 2.6 and Later Read More »
