TCP/IP stands for Transmission Control Protocol/Internet Protocol and it is a suite of protocols used to interconnect network devices on the internet. It requires a little central management and is designed to make networks reliable with ability to recover failures.

There are 4 layers in TCP/IP:

1. Application Layer:
   • Provides standardized data exchange
   • Payload is actual application data
   • Protocols: HTTP, FTP, Post Office Protocol3 , SMTP
2. Transport layer:
   • Maintains end-to-end communications across networks
   • Protocols: TCP, UDP
   • TCSP handles communication between hosts and provides flow control and reliability
3. Network Layer:
   • Also called Internet Layer
   • Deals with packets
   • Connects independent network to transport packets
   • Protocols: IPV4, IPV6 and Internet control Message Protocol
4. Network interface layer:
   • Also called as, Physical layer or Data Link layer
   • Consists of protocols that operate only on a link: the network component that interconnects hosts in the network
   • Protocols: Ethernet for local area network, Address Resolution Protocol

The main drawback of TCP/IP is, it is not easy to replace protocols involved and it is vulnerable to synchronization attack which is type of DOS(Denial-of-service).