Public Draft

Typical /24 IPv4 range

192.168.0.0 Network

192.168.0.1 Gateway

192.168.0.255 Broadcast

(IETF) document RFC-1918 , Private IPv4 ranges reserved by the IANA.

10.0.0.0/8 IP addresses: 10.0.0.0 – 10.255.255.255
169.254.0.0/16  IP addresses: 169.254.0.0 -  169.254.255.255  (APIPA - Automatic Private IP Addressing)
172.16.0.0/12 IP addresses: 172.16.0.0 – 172.31.255.255
192.168.0.0/16 IP addresses: 192.168.0.0 – 192.168.255.255

Subnet mask

Class A - 16 777 214 adresses

Public IP Range: 1.0.0.0 to 127.0.0.0

11111111.00000000.00000000.00000000

255.0.0.0

/8

126 networks

Class B - 65 534 adresses

Public IP Range: 128.0.0.0 to 191.255.0.0

11111111.11111111.00000000.00000000

255.255.0.0

/16

16,382 networks

Class C - 256 adresses

Public IP Range: 192.0.0.0 to 223.255.255.0

11111111.11111111.11111111.00000000

255.255.255.0

/24

2,097,150 networks

Class D - Multicasting t.ex. IP-TV

Range: 224.0.0.0 to 239.255.255.255

Class E - Only for research, not available for general use

Range: 240.0.0.0 to 255.255.255.255

Bits and their value:

256 128 64 32 16 8 4 2 1

/24 = 256 IP addresses

/23 = 512 IP adressess

/26 = 64 IP addresses

255.255.255.254 Point-to-point. No broadcast or gateway needed.

127.0.0.1 to 127.255.255.255 - Internal test adresses (loop-back).

Subnetting

Using a subnet mask of 255.255.255.192, your 192.168.123.0 network then becomes the four networks 192.168.123.0, 192.168.123.64, 192.168.123.128 and 192.168.123.192. These four networks would have as valid host addresses:

192.168.123.1-62 192.168.123.65-126 192.168.123.129-190 192.168.123.193-254

Remember, again, that binary host addresses with all ones or all zeros are invalid, so you can’t use addresses with the last octet of 0, 63, 64, 127, 128, 191, 192, or 255.

IP in Excel

=“192.168."&ROWS($A$1:A1)&".1” in some cell and then dopy down