DNS (Domain Name System) is the system that translates an Internet or Host name (that is easier for people to remember) to an IP address. In this article we’ll describe how DNS works, what port numbers are used for DNS protocol etc so keep reading for all info below. What is DNS A Domain Name […]
How to Configure Static Routing on Cisco IOS Routers (Examples)
Cisco IOS Routers support both static and dynamic routes. In small networks (2 to 5 routers) I would suggest to configure only static routes, especially if the network is not going to change much over time. Of course dynamic routing (using dynamic routing protocols such as RIP, OSPF, EIGRP) is much more flexible and scalable […]
What is a Subnet Mask Used For (on Routers and Hosts)
This is a post for people new to networking that have just started learning IP addressing and the basis of routing and subnetting. Every host or device on a TCP/IP network MUST have an IP address assigned in order to communicate with other devices. An IP address consists of a network part and a host […]
10 Best Computer Networking Books for Beginners & Experts
I have read tens of books (both in ebook format and also hard copy textbooks) in my networking professional career over the last 18 years. In fact, all of my preparation for my Cisco and other IT certifications was based on book studying (in addition to hands-on practice of course). Personally, I believe that having […]
Intelligent DDoS Mitigation System – IDMS Compared to Firewall & IPS
As e-commerce continues to proliferate and deliver profitable results, more business is being done online. The growing adoption of online retailing, Internet banking, cloud-based data storage and other commercial services represents a natural evolution of Internet use. For online businesses, however, any downtime can dramatically impact the bottom line. As a result, the growing scale […]
How to Ping a Network Port (TCP) Number to Verify if its Open
In this article I’ll describe a few ways to verify over the network if a remote TCP port on a host is open or not. This is a popular troubleshooting method to identify if a specific service or application is running on a remote server or computer. As you might know already, when an application […]
Ubiquiti Unifi Security Gateway (USG) Vs Edgerouter 4/Lite
Ubiquiti manufactures networking products (routers, switches, wireless etc) that can serve in a broad range of implementation cases, from Home networks up to large Enterprise environments. The USG (UniFi Security Gateway) and EdgeRouter devices are two product lines that target a similar market – I would say the SOHO and SMB enterprise market (although there […]
Differences Between TCP and UDP in IP Communication Networks
TCP (Transmission Control Protocol) and UDP (User Datagram Protocol) are both Layer 4 transmission protocols in the OSI model. However, these two protocols are quite different. From a high level view you could say that TCP is reliable and UDP is unreliable. Why then would we use UDP? UDP Characteristics Due to UDP being able […]
Best Ethernet Switches of 2021 – Gigabit-Managed-Unmanaged
Ethernet Switches are the backbone of any network, no matter if it’s a home, office or enterprise network. Even though most of our communication nowadays is carried out wirelessly (WiFi, Mobile 3G-4G-5G etc), there ARE a lot of cases whereby network connectivity has to be implemented the “old-school” wired way. And that’s where Ethernet Switches […]
Classless InterDomain Routing (CIDR) Cheat Sheet – Guide & PDF Download
CIDR was invented to facilitate better and more efficient allocation of IP addressing and especially IPv4 addresses which started running out pretty fast when the whole Internet accelerated its pace during the last 2-3 decades. What is Classless Inter-Domain Routing (CIDR) As you know, an IPv4 address consists of 32 bits and is represented as […]
Different Types of Ethernet Cables for Connecting Computers to a Network
If you have studied the OSI model with its 7 Layers that describe communication on computer network systems, you should know that the Ethernet standard lies in Layer 1 (Physical) and Layer 2 (Data-Link) of the OSI model. In this article we will focus on the physical (Layer 1) part of Ethernet, which mainly focuses […]
Difference Between LAN and WAN Networks – Compared and Explained
Networking is at the center of all information sharing and Internet activities, and most homes and businesses have some sort of networking technology used for internet access and for enabling the business communications and functions. However, many people struggle with some of the fundamental concepts involved in computer networking. Both Local-Area Networks, or LANs, and […]
What Is the Difference Between Internet and Intranet?
The internet and intranet are closely related terms. Some individuals may get these terms confused or use them interchangeably. While there are similarities, the internet and intranet are used for very different purposes. What Is an Internet Network? When you visit a website or use a mobile app that requires an internet connection, you are […]