Virtualization 4 of 4 – Networking

Virtual LAN (VLAN) Although VLAN emerged before virtualization and is not part of virtualization topic. I’d just like to start from here as a refresher. Suppose we have computers from finance department and computers from sales department all connected to a single layer-2 switch. There are at least three problems: 1) too many devices on … Read moreVirtualization 4 of 4 – Networking

High Availability and Load Balancer

Overview Fault tolerance and high availability are two architectural characteristics that people often confuse with each other. High availability focuses on minimizing downtime. It guarantees uptime, but not performance in the event of component failures. Fault tolerance, on the other hand, focuses on stable capacity event in the event of component failures. Fault tolerance is … Read moreHigh Availability and Load Balancer

Networking basics 2 of 3 – Layer 4 and common network configurations

Transport Layer Transport Layer handles multiplexing & de-multiplexing through ports. Port is more or less a virtual concept. Source port is usually ephemeral. Two dominant protocols are TCP and UDP. TCP relies on acknowledgement. TCP control flags are SYN, ACK, FIN, URG, PSH, RST, ECE, CWR. TCP connection is established by 3-way handshake and torn … Read moreNetworking basics 2 of 3 – Layer 4 and common network configurations

Networking Basics 1 of 3 – Layer 1 through Layer 3

What layer model works the best? Back in university my textbook was based on OSI 7-layer model. It is rigorously defined and often used in academics. When it comes to day-to-day operation, the 5-layer TCP/IP model is more useful. It combines Application, Presentation and Session layers in OSI model into a single Application layer. Physical … Read moreNetworking Basics 1 of 3 – Layer 1 through Layer 3