TCP/IP Protocol Suite

TCP/IP is the protocol of communication that we use on networks around the world.

OSI model was never meant to be a just a model, it was a competing standard to TCP/IP back in the days of the 1970. It was actually a competing protocol that people developed called the OSI protocol. There was a competition between TCP/IP and OSI protocol. And TCP/IP ended up winning. Although OSI was a better protocol but reason that why it didn’t end up winning was that its addresses were far too complex. So the physical construction of devices was complicated in this case. It had too many addresses, it used hexadecimal, and there were tones of address that could be use.

The next version of TCP/IP protocol called IPv6 looks like old OSI protocol. OSI model is still used to explain network communication.

TCP/IP model is also called DOD (department of defense) model. It actually maps up to the OSI model and boils its top three layers down into one big Application Layer.

OSI model tells how network communicates.

What actually happens is TCP/IP.

TCP/IP is not just one protocol, it’s a sweet of protocols it’s a team it’s a protocol suite that makes the things happen.

IP: is responsible for addressing packets. To help them get from their source to their destination. IP is just a subcontractor piece of TCP/IP; it is IP, network layer of the model, define source and destination IP address. 

SMTP: is responsible for email.

Application layer protocols: RIP, DNS, SMTP, TELNET etc begin the whole network communication process.

 

 

Every interface of a router represents a different network.

ARP: is always a broadcast message.

Microsoft MAC Format:               xx : xx : xx : xx : xx : xx        (12 hex digits, 48 bit)

Cisco MAC format:                  xxxx : xxxx : xxxx                  (12 hex digits, 48 bit)

Computers never speak directly to IP address, they can’t do it, and they only speak to MAC addresses.

Router stops broadcast.

Cisco recommends that you should not go beyond 500 hosts in a network. If you do so, the broadcast traffic can affect the performance of PCs that are attached to the network.

Loopback address for testing 127.X.X.X

Auto-configuration range 169.254.X.X