A previous post mentions how to send raw packets using winsock api on windows xp. Winpcap is a packet driver useful for packet capturing and sending raw packets on the windows platform. Raw means we have to cook the whole packet ourselves. A TCP packet for example consists of: 1. Ethernet header 2. IP header 3. TCP header 4. The data supposed to be send PACKET = ETHERNET_HEADER + IP_HEADER + TCP_HEADER + DATA Each [...]

Port Scanning searches for open ports on a remote system. The basic logic for a portscanner would be to connect to the port we want to check. If the socket gives a valid connection without any error then the port is open , closed otherwise (or inaccessible, or filtered). This basic technique is called TCP Connect Port Scanning in which we use something like a loop to connect to ports one by one and check [...]

The Huawei MT882 ADSL Modem that you might have received with your BSNL Broadband connection can be used to connect 2 computers to the internet simultaneously since it is a router. It has a USB interface and an Ethernet interface both of which can be simultaneously used but with a few setting changes. First of all one PC must use the usb interface and another must use the ethernet interface via a network adapter. That [...]