Whenever there is a new attack on the Internet that has anything to do with BGP (Border Gateway Protocol), you hear the commonly used phrase that goes something like “BGP is based on the inherent trust model with no inbuilt security”. While that is true (as we will see in …
Read More »How VoIP apps like Skype, WhatsApp, and Facebook Messenger work
I went on holiday recently and visited another country 3000 miles from mine. Of course, this means I had long left the reach of my mobile network operator. Due to roaming and partnerships between mobile network operators in different countries, I had the option of making and receiving voip calls …
Read More »Traffic Policing vs. Traffic Shaping
One of the ‘hot’ topics when studying about Quality of Service (QoS) is Traffic Policing versus Traffic Shaping. In this article, we will look at these QoS features individually, compare them, and also see how they are used in the real world. Network Quality There are four major factors that …
Read More »Software Defined WAN: the Wide Area Network is getting a facelift
The Networking world is being bombarded by so many “new” technologies that it is difficult to keep up with them all, from Software Defined Networking (SDN) to Network Function Virtualization (NFV) and now Software-Defined Wide Area Network (SD-WAN). At the center of all these technologies is a focus on software …
Read More »Open Networking from theory to practice
In this article, we will be discussing Open Networking and try to dissect what the “open” in Open Networking really means. We will also be looking at different real-life products and solutions that fit the Open Networking model. Finally, we will look at a practical lab example of Open Networking. …
Read More »MPLS in the SDN Era: Thin and Thick Routers
Thinness and thickness are architectural concepts, to the point that both types of routers might even be virtualized. Strictly speaking, thin and thick routers is SDN (Software Defined Network) jargon rather than industry standard language. These terms are getting more and more widely used and they are so meaningful and …
Read More »Subnet Zero and All-Ones-Subnet explained
In this article we are going to explain what the ip subnet zero is, but first we need to introduce subnetting. The Subnetting is used to partition a network into sub-networks (also called subnets) that are smaller in terms of addressing space. The first and the last subnets calculated during the …
Read More »GGP, EGP and 25 years of BGP: a brief history of internet routing
Although there was the ARPANET before it, the internet as we know it today came about in the early 1980s when TCP/IP was invented. Even back then, the nascent internet was a network of networks, and those newfangled IP packets needed to be routed from one organization’s network to another …
Read More »BGP Route Reflectors and their benefits
If you decided to read the content of this post, you probably know something (or a lot) about Border Gateway Protocol (BGP) and its benefits. Or I might be wrong, and you have heard about this cool protocol numerous times, but just did not figure out how it works. In either …
Read More »Router Stuck in ROMmon Mode
If you have ever experienced the ROMmon mode problem, you probably came across one of the following: configuration register forced the router to go to ROMmon mode during the boot process corrupt image (IOS) on Flash (indicated by bad_checksum message) router was unable to find the IOS (either on Flash …
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