Simply having a wired or wireless physical connection between end devices is not enough to enable communication. For communication to occur, devices must know “how” to communicate. Communication, whether face-to-face or over a network, is governed by rules called protocols. These protocols are specific to the type of communication method occurring. For example, consider…
Knowing the OSI reference model and the TCP/IP protocol model will come in handy when you learn about how data is encapsulated as it moves across a network. It is not as simple as a physical letter being sent through the mail system. In this article, I will be talking about some of the facts…
In my previous article, I have talked much about how data travels across the network. In this article, I want to talk more about MAC addresses and IP Addresses. Follow me as we will look at that in this article. There are two primary addresses assigned to a device on an Ethernet LAN: Physical…
If your network is using the IPv4 communications protocol, the Address Resolution Protocol, or ARP, is what you need to map IPv4 addresses to MAC addresses. This topic explains how ARP works. Every IP device on an Ethernet network has a unique Ethernet MAC address. When a device sends an Ethernet Layer 2 frame, it…
Application layer programs generate data that must be exchanged between the source and destination hosts. The transport layer is responsible for logical communications between applications running on different hosts. This may include services such as establishing a temporary session between two hosts and the reliable transmission of information for an application. The transport layer has…
You already know the fundamentals of TCP. Understanding the role of port numbers will help you to grasp the details of the TCP communication process. In this topic, you will also learn about the TCP three-way handshake and session termination processes. Each application process running on a server is configured to use a port number….
The Dynamic Host Configuration Protocol (DHCP) for IPv4 service automates the assignment of IPv4 addresses, subnet masks, gateways, and other IPv4 networking parameters. This is referred to as dynamic addressing. The alternative to dynamic addressing is static addressing. When using static addressing, the network administrator manually enters IP address information on hosts. When a…
The webservers that we so often connect to using names like www⋅cisco⋅com, are actually reached by assigning IP addresses to packets. On the internet, these domain names are much easier for people to remember than an IP address such as 74.163.4.161. If Cisco decides to change the numeric address of www⋅cisco⋅com, it is transparent to…
The network devices that people are most familiar with are end devices. To distinguish one end device from another, each end device on a network has an address. When an end device initiates communication, it uses the address of the destination end device to specify where to deliver the message. An end device is…
Now that the router has determined the best path for a packet based on the longest match, it must determine how to encapsulate the packet and forward it out to the correct egress interface. The figure explains how a router determines the best path to use to forward a packet. The figure depicts how…
When it comes to general security breaches, home networks are the most susceptible to attacks. The reason is that home network users always have the mindset that they have nothing that the hacker will be interested in. That is why most times, they do not always take the security of their devices serious. In this…
IP was designed as a Layer 3 connectionless protocol. It provides the necessary functions to deliver a packet from a source host to a destination host over an interconnected system of networks. The protocol was not designed to track and manage the flow of packets. These functions, if required, are performed primarily by TCP at…
In this article, I want to look at common network security monitoring tools in cybersecurity. Follow me as we look at this together in this article. Common tools that are used for network security monitoring include: Network protocol analyzers such as Wireshark and Tcpdump NetFlow Security Information and Event Management Systems (SIEM) …
“All networks are targets” is a common adage used to describe the current landscape of network security. Therefore, to mitigate threats, all networks must be secured and protected. This article will look at network security topology in Cybersecurity. This requires a defence-in-depth approach. It requires using proven methods and a security infrastructure consisting of…
A Denial of Service (DoS) attack creates some sort of interruption of network services to users, devices, or applications. In this article, I want to discuss all that you need to know about the Denial Of Service attack in Cybersecurity, Follow me as we will look at that in this article. There are two major…
Reconnaissance is information gathering. It is analogous to a thief surveying a neighbourhood by going door-to-door pretending to sell something. What the thief is actually doing is looking for vulnerable homes to break into, such as unoccupied residences, residences with easy-to-open doors or windows, and those residences without security systems or security cameras….
Ethical hacking involves using many different types of tools to test the network and end devices. To validate the security of a network and its systems, many network penetration testing tools have been developed. However, many of these tools can also be used by threat actors for exploitation. In this article, I am going to…
In my previous article, I talked about how online shopping has made life easy for people making transactions online. Despite the fact that it is very easy to make transactions online using credit and debit cards, you need to follow some guidelines in order to secure your funds. In this article, I want…
In my previous article, I have talked about some of the facts that you need to know about network security. This article talks about some of the facts that you need to know about IP Vulnerabilities in Networking. Follow me as we are going to look at that in this article. There are different…
Hosts broadcast an ARP Request to other hosts on the network segment to determine the MAC address of a host with a particular IP address. All hosts on the subnet receive and process the ARP Request. The host with the matching IP address in the ARP Request sends an ARP Reply. This article talks…