TCP/IP is a set of protocols .computers to share resources across
a network or internet .
TCP/IP also called as Internet protocol suite .
TCP - Transmission Control Protocol
IP - Internet protocol ..
UDP - user datagram protocol .
ICMP - Internet Control Message Protocol
What is IP Address ?
IP address is an 32 bit number ( hexa decimal number ) assigned for a computer on internet for identity .every computer connected to internet will hve a single and unique IP address ..It is composed of two parts Network number and host number .IP address or number is expressed as four decimal numbers separated by periods .
Ports of virtual software ports for data transmission in the internet the total ports are 0 to 65535. ports .
Well Known Ports are those from 0 to 1023.
The Registered Ports are those from 1024 to 49151
The Dynamic or Private Ports are those from 49152 to 65535
Any Two or more computer connected in internet by sending or receiving data packets .
Individual TCP packets contain "flag bits" which specify the contents and purpose of each packet. For example, a packet with the "SYN" (synchronize) flag bit set is initiating a connection from the sender to the recipient. A packet with the "ACK" (acknowledge) flag bit set is acknowledging the receipt of information from the sender. A packet with the "FIN" (finish) bit set is terminating the connection from the sender to the recipient.
some important tasks and port number in use :
TCP port no : 21 File Transfer ftp
TCP port no : 22 SSH Remote login
TCP port no : 23 Telenet
TCP port no :25 SMTP ( Simple Mail Transfer )
TCP port no :79 Finger
TCP port no :80 HTTP (world wide web) www
TCP port no 107 Remote Telenet service
TCP port no :115 sftp ( Simple File Transfer Protocol )
TCP port no : 118 SQL service
TCP port no : 139 NETBIOS Session Service
TCP port no : 257 SET ( Secure Electronic Transaction )
TCP port no : 445 Microsoft-DS
TCP port no : 1053 Remote Assistance
And many more port for different aplications and different purpose .
