Steganography is the science of hiding information or transmitting secret messages in a given host carrier for the purpose of enhancing value through undetectable covers. The paper focuses on the existent methods used with ipv4 and studies the various algorithms. Transfer of data over the internet crosses the different layers of the TCP and IP protocols. Each layer has its own characteristics, which indicate the scenarios in which it can best be used. Information can be hidden in the transport and network layers by usage of optional fields, semantic changes, and improper but acceptable construction of protocol data units (packets). Protocol steganography is the scheme to bypass the firewall. The TCP/IP has the following hidden channels namely the manipulation of HTML, XML, HTTP, UDP, TCP, IP, ICMP, Ethernet (CSMA/CD) in the four layers respectively.