ccna teacher

IP Address Classes
Class A 1 – 127 (Network 127 is reserved for loopback and internal testing)
Leading bit pattern 0
00000000.00000000.00000000.00000000
Class B 128 – 191 Leading bit pattern 10
10000000.00000000.00000000.00000000
Class C 192 – 223 Leading bit pattern 110
11000000.00000000.00000000.00000000
Class D 224 – 239 (Reserved for multicast)
Class E 240 – 255 (Reserved for experimental, used for research)


Private Address Space
Class A 10.0.0.0 to 10.255.255.255
Class B 172.16.0.0 to 172.31.255.255
Class C 192.168.0.0 to 192.168.255.255

Default Subnet Masks
Class A
255.0.0.0
Class B
255.255.0.0
Class C
255.255.255.0


2n where N is the number of bits in the subnet mask. IE, 2^4 = 4 bits of host space = 16 host addresses, minus 2, an address for the "network" and an address for being on a multiaccess network (broadcast address).

Example... 192.168.1.16/28 (32 minus the number of bits = 28). So, you have 2^N hosts, which means you have 192.168.1.16, .17, .18...29,.30,.31,.32 but, you loose the all 0's bits (0000) and the all ones (1111) as these have a significance. The 0000s would be 192.168.1.16 (the network address) and the 1111 would be the broadcast address, which would be 192.168.1.31
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Dear There are two sub-layers in Data link Layer that is Mac layer and Logical link layer.MAC defines how packets are placed on the media. LLC is responsible for identifying Network Layer protocols and encapsulating them..LLC header tells the data link layer,what to do with a packet once a frame is received.

data packets are placed on the media by encoding ...

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What is a Network Switch: Unmanaged Switches

An unmanaged switch works right out of the box. It's not designed to be configured, so you don't have to worry about installing or setting it up correctly. Unmanaged switches have less network capacity than managed switches. You'll usually find unmanaged switches in home networking equipment.
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What is a Network Switch?

To understand basic networking, you first need to answer the question, "What is a network switch?"

Most business networks today use switches to connect computers, printers and servers within a building or campus. A switch serves as a controller, enabling networked devices to talk to each other efficiently. Through information sharing and resource allocation, switches save businesses money and increase employee productivity.
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