OpenVZ – Open Source VPS Software

OpenVZ is an Operating System-level server virtualization solution, built on Linux. OpenVZ creates isolated, secure virtual environments VEs (otherwise known as virtual private servers, or VPS) on a single physical server enabling better server utilization and ensuring that applications do not conflict. Each VE performs and executes exactly like a stand-alone server; VEs can be rebooted independently and have root access, users, IP addresses, memory, processes, files, applications, system libraries and configuration files.
Using premier VPS technology, several isolated VPS systems are installed on a single physical server. Users share systems resources, such as the CPU and memory, but unlike shared hosting the file system is fully partitioned so they are not affected by other activities on the server. This means that up-time is more consistent, while root access to the server provides the flexibility to add and change modules and install your own software. Continue reading…

IPTables

IPTABLES

Introduction

The Internet Protocol (IP) is a data oriented protocol that allows multiple hosts to talk to each other across network connections. Data in an IP network are sent in blocks referred to as packets or datagrams. They typically have a source host, destination host, and source and destination ports associated with the communication. Layered on top of the IP protocol are other protocols. These are typically transport layers. There are two main transport protocols that are heavily used. Transmission control protocol (TCP) is a stateful delivery mechanism that makes a best effort to deliver the packets requested. If the first attempt fails, multiple attempts are made to route and deliver the packet. This protocol is very good at delivering text files that can not tolerate data corruption. With this protocol clients have the ability to request redelivery of packets that were not properly received and can handle our of order delivery of packets. This protocol is very good for applications like patch delivery, email, network file shares, and web pages. It is not very good for delivery of streaming video or voice over IP applications. Continue reading…