BBC Start Blocking VPN Access from Abroad

Many people use VPNs (Virtual Private Networks) for security reasons, primarily because they create a secure, encrypted tunnel across the open architecture of the internet.  Many firms use them as a secure method of allowing remote users to access corporate file servers and email systems from anywhere in the world.  It has to be said […]

Is it Ok to Bypass Internet Filtering?

The internet of course traverses the globe and one of the difficulties in this scale is the problems of laws and the jurisdiction of  law.  After all calling the Thai Royal family names might be illegal in Thailand, but it certainly isn’t in Chicago.  All over the world there are hugely different laws, rules and […]

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 […]