CCNA R&S

After long time I give some time to share my knowledge.

This time I will share IP Addressing and their classes with you.

– There are 4 octets decimal dotted format in IPv4. like 192.168.1.1

– This 4 octets in binary form : 00000000.00000000.00000000.00000000.

– There are five classes in IPv4 Addressing.

1) Class A 2) Class B 3) Class C 4) Class D 5) Class E.

– Class A : 0-126 (remember 127 reserved for loopback), Default Mask : 255.0.0.0, N.H.H.H, 11111111.00000000.00000000.00000000, CIDR : /8.

– Class B : 128-191, Default Mask : 255.255.0.0, N.N.H.H, 11111111.11111111.00000000.00000000, CIDR : /16.

– Class C : 192-223, Default Mask : 255.255.255.0, N.N.N.H, 11111111.11111111.11111111.00000000, CIDR : /24.

– Class D : 225-239 (224 is reserved for Multicast Addresses), This Class Addresses we can not use.

– Class E : 240-254, This Class Addresses also we can not use.

Best of Luck

–

This is not a Physical model
This model divides the network communication process in smaller and simpler component.
This is very useful tools for network Troubleshooting
There are seven layers in OSI Model
- layer 7 – Application Layer
- layer 6 – Presentation layer
- layer 5 – Session layer
- layer 4 – Transport layer
- layer 3 – Network layer
- layer 2 – Data Link layer
- layer 1 – Physical layer
Layers 7, 6 and 5 (Upper layers) main focus on services to application
Layers 4,3,2, and 1 (Lower layers) main focus on end to end data delivery
Data Unit in L4 is called Segment
Data Unit in L3 is called Packet
Data Unit in L2 is called Frame
Data Unit in L1 is called Bits
Encapsulation – Data moves down (7>6>5>4>3>2>1)
Decapsulation – Data moves up (1>2>3>4>5>6>7)

amirkhalak