what is IP address:
IP address is a logical address of the computer and is used to uniquely locate computer connected via a network.A computer without IP address Can never share or receive data over internet.IP stands for Internet Protocol.
what is MAC address:
MAC address is a physical address of the computer and it is useful to identify a computer in a Network for eg LAN(local area network).It is assigned by the manufacturer of hardware so it is also called as hardware address.Without Network Interface Card no computer cannot connect in any network. NIC card stores MAC address of a computer.MAC stands for media access control.
what is PORT address:
PORT address is a logical address of an application.OS maintains the PORT address of some popular applications.
CASE STUDY 1:
Consider above Case1:
IF a computer A wants to communicate with computer B then A requires following mandatory points
- IP address of A and B
- Mac address of A and B
- Port address of A and B
NOTE: DNS (Domain Name System) gives the destination IP address of PC
Now, A has IP address and Port address of itself and B Computer but it doesnt have MAC address of B Yet.As soon as the packet or request goes to College router the college routers identifies the IP for which the request is came and assumes that this IP is of our College computer and passes the request to switch and switch holds all the mac address of Its network for eg Computer B and then switch forwards the request to B computer.
Now,the request is arrived till the computer B but computer B contains no of applications and this request should be given access to the application for which computer A has given port no so in simple words OS maintains the list of Port address.For example A has sent Email to B then it will be accessed by PORT NO 25 which is simple mail transfer protocol(SMTP).Finally Email is delivered and User B can read that mail…