Today I will be discussing a two-tier topology called “Spine and Leaf.” This is a popular data center topology that uses a “partial mesh” set up to optimize east-west traffic within the network. East-West traffic refers to data communication that occurs between devices, servers, or systems within the same data center, cloud environment, or internal…

Today I will be discussing the “Three Tier Model” and the “Collapsed Core Model.” The three tier design consists of three tiers while the collapsed core is two layers. The collapsed core is used when the costs do not justify having a complex three tier setup and to minimize unnecessary complexity. The functions (layers) that…

Today I will be discussing topology types including full mesh, partial mesh and star.Every topology type has their own unique strengths and weaknesses when it comes to implementation.  Star- The first topology type I will be discussing is a “star” topology. A star topology is a network design in which each device in the topology…

Today I am going to discuss a layer 2 security feature called port security. Port Security is used on switches to control and restrict access to a switch port based on the MAC address of the connected device. The restrictions can either be by only allowing a specific MAC address on a port, and/or only…

Today I will be discussing DHCP snooping. DHCP snooping is a layer 2 security feature used on switches that prevent rogue DHCP server attacks. It does this by filtering DHCP messages based on trusted/untrusted ports and building a binding table of legitimate IP to MAC to VLAN to switch port mappings.DHCP Starvation- DHCP is an…

Today I am going to talk about QOS scheduling. Scheduling is a QOS mechanism that determines the order and timing at which packets are taken from queues and sent out over a physical network link. Different types of scheduling are round robin, CBWFQ (Class Based Weighted Fair Queueing), and LLQ (Low Latency Queue.)  Round Robin-…

Today I am going to continue to talk about QOS (Quality of Service). QOS is used on network devices to classify and mark traffic based on their priority level, allowing for higher priority traffic to receive different treatment than lower priority traffic as it moves through the network. The steps of QOS are: Classification- When…

Today I am going to talk more about QOS and the congestion avoidance and management behaviors that take place. One of the major reasons why performance lacks in networks is because there is either not enough bandwidth or there are too many devices/applications competing for bandwidth. They can be either, but both reasons lead to…

Today I am going to talk about QOS (Quality of Service) and the criteria that impacts how well an application or service performs. QOS is a mechanism used to classify, mark, and prioritize certain kinds of traffic to ensure they perform well under congestion. This allows for critical applications and services to maintain performance despite…

Today I am going to be discussing POE (Power Over Ethernet). POE is a technology that allows for electrical power and data to be transmitted over the same ethernet cable. This allows for network devices such as IP phones, IP cameras and WAP to operate without having to worry about having a separate power supply. …