Overview

Tunneling is a mechanism that makes transfer of payloads feasible over an incompatible delivery network. It allows the network user to gain access to denied or insecure networks. Data encryption may be employed to transport the payload, ensuring that the encapsulated user network data appears as public even though it is private and can easily pass the conflicting network.

An information center hosting hundreds of thousands of customers located across many locations with virtualized customer workloads will most likely need many VLANs and at the same time the ability to share assets on each other networks. VXLAN/ NVGRE SUPPORT Software Defined Networking (SDN) was created partly to solve problems associated with multi-tenant environments. This wide resource sharing enables Microsoft to create NVGRE for Hyper-V, a native hypervisor that can create virtual machines on x86-64 systems starting with Windows 8 and VMware to create Virtual Extensible LAN (VXLAN), a tunneling protocol that recognizes network users to access or provide networking services to networks that does not support or provide directly.

NVGRE standard is proposed by Microsoft, Intel, HP and Dell.
VXLAN specification was originally created by Cisco, VMware, and Arista Networks

Overview

• passenger protocol(inner)
  The type of protocol (IPv4, IPv6, or MPLS) used by the networks that are connected by a GRE tunnel. Packets that are encapsulated and routed across the transport network are payload packets.

• encapsulation protocol(gre)
  The type of network layer protocol (GRE) used to encapsulate passenger protocol packets so that the resulting GRE packets can be carried over the transport protocol network as the packet payload.

• transport protocol(outer)
  The type of protocol (IPv4) used by the network that routes passenger protocol packets through a GRE tunnel. The transport protocol is also called the delivery protocol.

Overview

What is a character encoding? In the end, when people do things with computers, they tend to work in text forms, whether that’s programs, or whether that is some other input that they give to the computer. It’s usually text. Text is conceptually a list of characters. That’s what separates it from random images on paper. The idea with character encoding is that the computers definitely would prefer numbers. We take these characters, we assign them numbers, integers. Then we figure out a way to transcribe those integers into a list of bytes. That whole process of going from text to a list of bytes is known as encoding. The reverse step is known as decoding. For example, this would be the standard ASCII approach to this. Hello is a five letter word, we will split that into five separate characters. Each of these characters is being assigned a number. At least in this case, we take these numbers and say, each of these numbers corresponds to 1 byte in the final output. Once you start working with more characters, that system breaks down because when you say each character is 1 byte, then you’re stuck with 256 characters. That doesn’t work for more complicated use cases like Chinese characters.

TLS, RSA, AES

Overview

It is a simple workload generator for POSIX systems. It imposes a configurable amount of CPU, memory, I/O, and disk stress on the system. It will stress test a server for the following features:

• CPU compute
• Cache thrashing
• VM stress
• Drive stress
• I/O syncs
• Socket stressing
• Context switching
• Process creation and termination
• It includes over 60 different stress tests, over 50 CPU specific stress tests that exercise floating point, integer, bit manipulation and control flow, over 20 virtual memory stress tests.
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Overview

The load balancer can be splitted into different part based on different types
By Component

• Hardware
• Software

By Type

• Local Load Balancers
• Global Load Balancers

By Deployment

• On-premise
• Cloud

Key Market Players

• A1o Networks, Inc.
• Amazon Web Services, Inc.
• Citrix Systems, Inc.
• F5 Networks, Inc.
• Google LLC
• IBM Corporation
• Microsoft Corporation
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Algorithm

Nginx now supports following load-balancing disciplines

• Round-robin and weighted round-robin
• Least-connected and weighted least-connected
• Source-ip hash-based, and a weighted one
• Generic hash
• Consistent hash
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checksum

A check sum is basically a value that is computed from data packet to check its integrity. Through integrity, we mean a check on whether the data received is error free or not. This is because while traveling on network a data packet can become corrupt and there has to be a way at the receiving end to know that data is corrupted or not. This is the reason the checksum field is added to the header. At the source side, the checksum is calculated and set in header as a field. At the destination side, the checksum is again calculated and crosschecked with the existing checksum value in header to see if the data packet is OK or not.

This article aims to explain how checksum is calculated, the method is used to calculate checksum. both IP and TCP uses the same method to calculate its checksum, IP checksum is only for IP header, while TCP checksum is for Pseudo IP header + TCP header + TCP payload.

Yaml

YAML is a human friendly data serialization standard for all programming languages, it’s superset of JSON.

minikube

There are several tools to setup Vanilla Kubernetes, like kubeadm, minikube, Kubespray, while minikube is to setup Vanilla Kubernetes locally, focusing on making it easy to learn and develop for Kubernetes.