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 […]
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In a previous post I explained how to configure VLANs on Cisco Switches. That was a simple scenario with just two switches connected with a trunk port and having shared VLANs belonging to both switches. Now, imagine the situation where you need to manage a huge Layer 2 switched network with tens or hundreds of […]
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The key difference between routers and switches in TCP/IP networks is that Switches primarily function to provide Layer 2 connectivity and Routers provide Layer 3 connectivity (as described in the OSI layer model). What exactly does this mean? From a high level view it means that switches allow hosts to communicate as long as they […]
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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 […]
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Throughout my career in TCP/IP networking (mainly with Cisco products) I have learned a very important lesson: Spending some time to create Documentation for your projects will pay dividends down the road. An important part of this Documentation is a network diagram/topology of your Network project. Moreover, another primary task you will need to perform […]
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I have been a Cisco certified professional since 2001 where I first passed my CCNA exam. A few months after that I managed to acquire also CCNP Routing and Switching and then CCSP (Security Professional certification which is not available anymore). During all these years I have experienced many changes in Cisco Certifications, some of […]
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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 […]
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The firewall is the cornerstone of security in computer networks and I.T in general. In this website I have been talking extensively about the Cisco ASA firewall which is a classic example of a hardware network firewall. However, there are some other types of firewalls used in large enterprises, SMB or even home networks. Some […]
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With the rise of distributed networks, finding a secure way to transfer files and data is essential. That’s where software products like Secure File Transfer Protocol, better known as SFTP, comes in. File Transfer Protocol has been around since 1971; the encrypted version was developed in 1994. This popular file transfer communication protocol is able […]
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I first got acquainted with TFTP at the beginning of my networking career. The first use-case of TFTP protocol is when I first upgraded the IOS firmware of a Cisco router using a little software utility called “TFTPD32”. Trivial File Transfer Protocol (TFTP) software provide a key service to many network and system administrators for […]
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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?
Table Of Contents
UDP Characteristics Due to UDP being […]
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PuTTY is a free terminal emulation tool that’s been available for 20 years. Originally released for Microsoft Windows, this versatile remote administration tool can be used to access workstations, servers, network devices etc using various protocols such as secure shell connection (SSH), Telnet, Rlogin etc. While it continues to be popular for accessing network devices […]
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In the Networking and IT world we usually design and implement networks and server infrastructure taking for granted that the hardware and applications will withstand any volume of traffic. Stress Testing a network or IT system with high volume of traffic will give us significant insights about the behavior of such systems in abnormal conditions […]
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