Edimax Technology ES-5240G+ 10000000.00000001.00000010.1 0000000, 1 0000000 1 1111111

Class D and E:

Class D is a class with first 4 MSB (Most significance bit) set to 1-1-1-0 and

is used for IP Multicast. See also RFC 1112. Class E is a class with first 4 MSB set

to 1-1-1-1 and is used for IP broadcast.

According to IANA (Internet Assigned Numbers Authority), there are three

specific IP address blocks reserved and to be used for extending internal network.

We call them private IP addresses and they are listed below:

Class A 10.0.0.0 --- 10.255.255.255

Class B 172.16.0.0 --- 172.31.255.255

Class C 192.168.0.0 --- 192.168.255.255

Please refer to RFC 1597 and RFC 1466 for more information.

Subnet mask:

It means the sub-division of a class-based network or a CIDR block. The

subnet is used to determine how to split an IP address to the network prefix and the

host address in bitwise basis. It is designed to utilize IP address more efficiently and

ease the IP network management task.

For a class B network, 128.1.2.3, it may have a subnet mask 255.255.0.0 by

default, in which the first two bytes are with all 1s. This means more than 60

thousands of nodes in flat IP address will be at the same network. It’s too large to

manage practically. Now if we divide it into smaller network by extending network

prefix from 16 bits to, say 24 bits, that’s using its third byte to subnet this class B

network. Now it has a subnet mask 255.255.255.0, in which each bit of the first

three bytes are 1s. It’s now clear that the first two bytes are used to identify the

class B network, the third byte is used to identify the subnet within this class B

network and, of course, the last byte is the host number.

Not all IP address is available in the sub-netted network. Two special

addresses are reserved. They are the ones which their host number are all zeros

and all ones. or example, an IP address 128.1.2.128/25; to represent the network

itself, the IP address is 128.1.2.128; and for IP broadcasting, the address used

would be 128.1.2.255.

10000000.00000001.00000010.1 0000000

25 bits

1 0000000 1 1111111

All 0s = 128.1.2.128

All 1s= 128.1.2.255

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