If you have had any experience with Cisco switches or routers, you know there are situations where a factory reset of the device is needed. Whether you want to reconfigure a device from scratch to get a clean configuration or repurpose a device to play a different role in the network, it’s always a good […]
About Lazaros Agapidis
Lazaros Agapidis is a Telecommunications and Networking Specialist with over twenty years of experience.
He works primarily with IP networks, VoIP, Wi-Fi, and 5G, has extensive experience in training professionals for Cisco certifications, and his expertise extends into telecommunications services and infrastructure from both an enterprise and a service provider perspective.
In addition to his numerous vendor certifications, Lazaros has a solid online presence as an expert in his field, having worked in both public and private sectors within North America and in Europe.
He has enjoyed sharing his practical experiences in writing as well as through engaging online training.
Follow Lazaros at LinkedIn: Lazaros Agapidis or at his Youtube Channel.
BGP Multihoming – Influencing Enterprise to ISP Routing Using BGP
BGP is the de facto routing protocol deployed on the Internet. Large enterprise networks will typically run BGP on the edge of their networks to ensure that routing between the ISP and the enterprise network takes place in the best possible way. It is possible to use BGP to modify the way that the ISP […]
The Most Important Border Gateway Protocol (BGP) Timers Explained
Border Gateway Protocol or BGP is a routing protocol that uses timers as part of its operation. Various timers perform different functions, and some are used for very specialized operations that are unique to BGP. In this article, we’ll be exploring some of the most common timers used for BGP as well as some less […]
Comparison of LLDP vs CDP on Cisco Networking Devices
Link Layer Discovery Protocol (LLDP) and Cisco Discovery Protocol (CDP) are network discovery protocols that perform similar functions. These protocols operate at the Data Link layer and are used by network devices to discover information about neighboring devices connected to a local network. Although LLDP and CDP operate in a similar manner, they differ in […]
Explanation and Comparison of OSPF E1 vs E2 Routes
Open Shortest Path First (OSPF) is a popular routing protocol used in many production networks throughout the world. Understanding route types is important when designing an OSPF topology for efficient and effective operation. Among the various route types OSPF offers, the External types E1 and E2 play an important role in importing routes from outside […]
Comparison of GRE vs IPSEC Used in TCP/IP Networks
Generic Routing Encapsulation (GRE) and Internet Protocol Security (IPsec) are two related but distinctly different technologies. They can be deployed separately but can also work together (GRE over IPSec) to deliver network tunneling and security services to networks and individual users. In this article, we’ll explore these technologies to understand them, and compare them to […]
How to Find a Device MAC Address on a Cisco Switch (show mac address-table)
When performing troubleshooting or maintenance tasks on an enterprise network, it is sometimes necessary to identify the MAC address of particular devices (hosts, other switches, other network devices) that are connected to the network. On smaller networks, this is somewhat simple to achieve, however, on larger networks, it can become a challenge. In this article, […]
Discussion and Explanation of OSPF Graceful Restart and Shutdown
OSPF is one of the most popular routing protocols for enterprise networks. It has been around since the 1980s and has been continually updated and revised to conform to the requirements of modern IP networks. As such, it is an extremely mature and robust routing protocol that can be tweaked and fine-tuned in many ways […]
Explanation and Configuration of OSPF MD5 Authentication on Cisco Networks
OSPF (Open Shortest Path First) is a dynamic routing protocol used in IP networks, primarily within large enterprise networks. In this article we will discuss and configure OSPF MD5 authentication on Cisco devices. Like other routing protocols, OSPF shares information about network topologies and prefixes between devices. This is done by exchanging messages between OSPF-enabled […]
Comparison of BGP Confederations vs Route Reflectors
When deploying excessively large Autonomous Systems or ASes in BGP, it is necessary to overcome the limitation introduced by the iBGP full mesh peerings required within the AS in question. There are two primary ways this can be achieved, using either BGP’s Route Reflector feature or BGP confederations. In this article, we’ll examine these two […]
What are BGP Confederations-Explanation and Discussion (With Cisco Example)
Border Gateway Protocol (BGP) is the de facto routing protocol that is deployed on the Internet at large. BGP is ideal for the Internet because of its scalability. One of the many characteristics of this routing protocol that make it so scalable is what is known as BGP confederations. In this article, we’ll discuss what […]
What is BGP Route Reflector – Explanation and Discussion (with Cisco Example)
Border Gateway Protocol (BGP) is the protocol of choice for routing on the Internet. BGP is also often used on the edge of corporate networks and is often the routing protocol of choice for large private enterprise networks. BGP needs to be extremely scalable to respond to these requirements. One of the ways that this […]
Explanation of BGP Neighbor Adjacency States on Cisco Devices
Border Gateway Protocol (BGP) is the fundamental routing protocol that is used on the Internet. Like most routing protocols, BGP depends upon the creation of neighbor adjacencies between BGP routers to exchange prefixes and routing information. In order to successfully create these neighbor adjacencies, they go through a series of neighbor adjacency states. In this […]