The Ins and Outs of a VPN

Any business that expands to multiple locations around the world requires a fast and reliable way to keep its data accessible by its employees, and for employees to connect to company's servers over a secure line from a remote location.

VPN, or virtual private network, is a technology that enables businesses to accomplish its goal of data secure and connectivity. It's a private network that connects remote sites or users together using a public network such as the Internet. The prime reason for using a VPN is that secures the data and prevents anyone intercepting the encrypted data from reading it.

Understanding How the VPN Works

The internet is like an ocean, which has various islands representing LANs. Just as travelling from one island to another via a ferry isn't private, in the same way, the wires and routers constituting the internet are not private. Essentially, any connection between two private networks using the internet is susceptible to security issues.

For obvious reasons, a business that uses the internet has to protect its data, and that is where the VPN enters. It allows users to communicate using the internet and connect with a private LAN in a secure and reliable manner. VPNs can also be expanded to accommodate more users from different locations.

Common Types of VPN

A site-to-site VPN is one common type of VPN that connects multiple fixed locations. It allows a business to extend its network making computer resources available to employees from one location to another. A company that is growing its offices in multiple locations around the world is a perfect example of a company in need of VPN.

The Two Types Of Site-To-Site VPNs Include:

Intranet based
An intranet VPN can be used to connect each separate LAN to a single WAN. It is suitable for companies that have one or more remote locations to be connected to a single private network.

Extranet based

An extranet VPN can be built between two companies that are closely related and wish to connect its LANs. The extranet-based VPN will allow the two companies to work in a shared network environment, which is secure and reliable.

About The Company
VPNFinder.com is an online VPN service review company that aims to help internet users make the best decisions when choosing a VPN service. The website provides the best reviews, which include price comparisons, features, and the editor's review of the VPN. All the reviews are based on real time usage, and professional opinions.

More about → The Ins and Outs of a VPN

Basic Network Management With SNMP

SNMP is a networking monitoring protocol that is incorporated within the TCP/IP suite of Internet protocols. It is used to monitor and manage devices remotely across a network and has 3 key components which are the managed devices, snmp agents and network management systems often just referred to as an NMS.

A managed device is an active network device such as a server, router, switch, workstation or in fact any device that is network capable. The managed devices are programmed to collect information from the host device, possible store that information and have the ability to forward that information to the Network Management Station.

An SNMP agent is a piece of software residing on a host network device which collects the programmed information and communicates that information in the form of SNMP Traps to the Network Management Station.

A Network Management Station is used to monitor and control SNMP host devices through a series of simple messages and also report that information to the network monitoring team in the form of some kind of alarm or report.

The NMS can run a number of application processes designed to gather information about known networked devices. This information can be status information such as a change in status of a Router interface or a Switch Port, device configuration changes or information relating to the performance of a managed device.

Often the software applications loaded onto Network Management Stations are proprietary, but do contain and operate with TCP/IP standards based SNMP. One good example of an SNMP application is HP Openview.

Devices that communicate with a NMS are often configured to be a member of a known community with a community string or password providing the community identity or authentication. Later versions of SNMP use a stronger form of Authentication and Encryption of SNMP messages. A NMS must be part of a community before it can receive or view messages or make configuration changes to the devices already part of the community.

The SNMP messages themselves contain the information from the managed device or instructions from the NMS in a data field and each message also contains the identity of the community to which the device belongs. The SNMP messages are sent across the network encapsulated within a UDP (User Datagram Protocol) packet, which in turn is encapsulated within an IP (Internet Protocol) packet.

The agent software installed on the host devices have what is known as a MIB (Management Information Base), which is a database containing a list of manageable objects on the device. When a device needs to inform the Network Management Station about a configuration or status change, it sends a message known as a TRAP to the community NMS informing of the change.
The NMS has a number of message types it can use to interrogate or make changes to configuration on the managed devices and these are:

GET - Is used to ask the managed device for certain information about a managed object on the device. It could be a request for status of a router interface or the amount of disk space on the device hard disk drive.

GET-NEXT - Used to request the value of the next managed object in the device MIB.

SET - This is where the NMS can actually change the value of a managed object's variable, providing the object allows READ / WRITE access. If READ Only then this will not be possible.

The Management Information Base on the managed device will contain hierarchically organized information which are identified by what are known as object identifiers, which are universally known.

More about → Basic Network Management With SNMP