CYBER SECURITY & NETWORKING

 In the last couple of writeups, we talked about various things related to protocols, IP addresses, MAC Addresses, etc. We used the term layers and we talked about various layers like layer 2, layer 3, etc for various terms and protocols and addresses. Here's where all these layers lie and it is the model that comprises of and gives information about these layers. We are going to talk about the OSI Model. OSI stands for Open System Interconnection and as the name suggests OSI model sets standards for the systems that are open to communicating with other systems. Sometimes during technical discussions, a switch may be referred to as layer 2 or a router as layer 3 so it is extremely important to have a good idea about the OSI model. The OSI model comprises 7 layers. An easy way to remember them is a sentence that goes like A P enguin S aid T hat N obody D rinks P epsi. (Top to bottom order) (If you're a Pepsi lover please don't get offended this is just for the sake of reme

 What is up guys! In this blog, I'm going to talk about What are ports? What are Protocols? What is TCP? What is UDP? etc. A Port is a place in the computer, which it uses to communicate and host various processes. We can easily relate this theory of Ports to a shopping mall. Imagine that you visit a shopping mall. What do you see there? A lot of shops right? Now, when you look at a centralized map of the mall, you'll notice the shop and its floor and number, etc. Thus each shop has it's own shop number and each shop provides some product to you.  Another example can be your own body itself!! If you want to speak, there's a particular place reserved for it, if you want to see things, there's a special place reserved for it, if you want to hear, there is a special place reserved for it and the list goes on. In the above examples, you can assume your body and the shopping mall as a computer system and the special places and the shops as ports. Similarly in computers,

Hello Guys, So last time we talked about IP Addresses which make up layer 3 (Network Layer) of the OSI Model and are also useful in routing. Today, we are going to talk about MAC Addresses which make up layer 2 (Datalink Layer) of the OSI Model. MAC stands for Media Access Control. MAC address is a 48-bit physical address that is embedded into the NIC (Network Interface Controller). These 6 sections are actually 6 octets. (FIGURE A)                                                                          (FIGURE B) The address that you see just next to ether is the MAC Address. This address is used by switches to communicate and know what the device really is. MAC address has the first 3 octets as their identifiers. These 3 octets or 24 bits form the OUI (Organisationally Unique Identifier) and the remaining 3 octets or 24 bits are NIC specific i.e. they depend on the NIC installed. Thus, we can say that (from figure B) the first 6 characters i.e. 98-28-A6 will be denoting the Organiza