Learning about Cloud Computing

Of all the latest technologies that are filling the news pages of the technological press – perhaps the most common is ‘cloud computing’. In effect this is a technology that is already playing a great part in most of our lives but what exactly is it? Cloud computing identifies the programs provided as services on […]

IP Fragmentation

Under UDP, the physical network layer will usually impose a upper limit on the size of the frame that it is able to transmit. So whenever the IP layer receives a data packet to send, it will first check on which interface the datagram is being sent on then queries the interface to find the […]

NFS – Network File System

NFS is the Network File System and is another application which provides almost transparent access to files for client applications. At the core of NFS lies Sun:RPC remote procedure Call which should be understood to consider NFS properly. Sun Remote Procedure Call For network programmers much of their work is done by creating application programs […]

IP Multicasting

Many applications use IP multicasting primarily for two distinct functions. The first one is to provide a delivery mechanism for multiple destinations. Many applications provide information to multiple recipients simultaneously, commonly used for things like delivering mail, news or updates. Other applications like conferencing and distributing video feeds to an audience. Without multicasting, these applications […]

Using ICMP Messages

Sometimes the Internet Control Message Protocol might not look very helpful when you’re trying to troubleshoot issues. However ICMP contains a lot of different message types and lots of them are in fact extremely useful for both troubleshooting and general network management tasks. Obviously the most used and famous command in ping which is focussed […]

Switching Around the World with a VPN

When you’ve got used to using a VPN service, you’ll slowly start to discover the various advantages of being able to switch countries when you like. For example although in the UK most of the Premiership Football matches are only available on subscription TV if you change your location to USA or Canada you can […]

Disguising Your Online VPN

For many of us, VPNs are an essential tool for using the internet in any capacity.  When you realise that everything you do online is logged and the majority of transactions happen in clear text then you start to be aware of how little privacy you have without one.   Imagine for example there is […]

Using the Simple Network Management Protocol

Networks used to be fairly straight forward affairs, you’d have some basic hardware like switches and hubs, a few servers and the rest would be the PCs which needed to talk to each other.  Normally you could buy all these from the same provider so you’d have some uniformity in hardware.  In fact the first […]

DNS Server Caching

In any internet enabled network, name resolution and in particular DNS requests represent a significant amount of traffic.    One of the important ways that DNS reduce this traffic is by caching or saving all the responses that they receive.  This is an important function which ensures the resolution process is more efficient than if […]