Blocking TCP requests on an Ethernet Network for Bandwidth Control
People have from time to time been eager to see what is going on in a network. Network administrators and higher level people have always been curious to know how their network resources are utilized. There are companies that want their professionals to use the Internet to increase their productivity, and these companies look at doing it by blocking some sites that are obviously very unproductive. Moreover people may also not like their employees visiting pornographic and other sites that are absolutely of no advantage to the company. Here we provide you with a paper that aids programmers to develop applications that can monitor a network tell which user accesses which site and also restrict the access of some users and sites that are of no advantage.
The previous paper titled - Monitoring Ethernet Networks with NDIS drivers clearly describes how we can capture all the packets that travel in the network and extract the URL that is contained in these packets. Briefly describing, if the Ethernet card of your computer is placed in a mode called the promiscuous mode then it accepts all the packets that come to it.
An Ethernet network is said to be a broadcasting network in the sense that it broadcasts all the packets that travel in the network. More clearly, every machine in the network will receive a copy of the packet that travels in the network. We use a driver and place the Ethernet card in the so-called promiscuous mode. Then we examine the header and the data of the captured packets to extract the URL contained in them. With these URLs that are obtained it is possible to find out the site the particular user has visited....
