ICMP Ping Flood A ping flood program sends a large of icmp packets to a remote host to flood the network and system resources on the target system. The target system keeps replying to the icmp packets and its system resources are consumed un-necessarily. In a previous article on we saw how to construct raw… Read More »
Communication over sockets involves 2 programs running on the same machine or on separate machines across a network. First is a socket server and the other is a socket client. Tcp stands for Transmission control protocol and it is the most common protocol being used for most of the network communication that takes place over… Read More »
UDP sockets UDP stands for User Datagram Protocol and is an alternative protocol to TCP the most common protocol used for data transfer over the internet. UDP is different from TCP in a number of ways. Most importantly UDP is a connectionless protocol. TCP vs UDP In the TCP protocol first a connection is established… Read More »
Socket programming with winsock This is a quick guide/tutorial to learning socket programming in C language on Windows. “Windows” because the code snippets shown over here will work only on Windows. The windows api to socket programming is called winsock. Sockets are the fundamental “things” behind any kind of network communications done by your computer…. Read More »
MAC Address Mac address (Media Access Control Address) or hardware address is a 48 bit (6 character) wide address assigned to a network interface. It is important for the packet delivery between 2 devices like your computer and the router. Ethernet protocol uses the mac address to deliver it to the right network node. It… Read More »
Tcp connect port scanning TCP connect() scanning is the most basic form of TCP scanning. The program performs a connect() command on those ports of the target machine which are to be checked. If the port is open then the connect() command will succeed and a connection will be established. If the port is closed… Read More »
Raw sockets with winpcap A previous post explains how to send on windows xp. However the winsock api has limited raw socket support in windows versions greater than windows xp+sp1. Therefore winpcap has to be used to send raw packets on higher windows versions. Winpcap is a packet driver useful for packet capturing and sending… Read More »
DNS Query When we type a web url or domain in our browser a dns request is immediately send by our browser to a DNS server to get the IP address of that web address. In winsock applications we achieve this by gethostbyname() and things are pretty simple. In this article we shall do this… Read More »
Winsock packet sniffer A packet sniffer is a program that can sniff the packets moving on the network. All applications communicate over the network with data packets where each packet contains part of the whole data being exchanged. A sniffer is able to pickup these individual packets and read them. In this post we are… Read More »
Raw sockets using winsock Raw sockets or “Raw Packets”, enable a program to access the entire contents of a packet or datagram, both for reading and writing purpose. In other words, you can fabricate a whole packet according to your likes and dislikes. For example, a TCP packet would contain an IP header, a TCP… Read More »