Example: Two Subnets; Table 51 Alternative Subnet Mask Notation - Nortel BCM50e Configuration

236 Appendix G IP subnetting
Table 51
notations.

Table 51 Alternative Subnet Mask Notation

Subnet mask IP address
255.255.255.0
255.255.255.128
255.255.255.192
255.255.255.224
255.255.255.240
255.255.255.248
255.255.255.252
The first mask shown is the class C natural mask. Normally, if no mask is
specified, it is understood that the natural mask is being used.

Example: two subnets

As an example, you have a class C address 192.168.1.0 with subnet mask of
255.255.255.0.
IP Address
IP Address (Binary)
Subnet Mask
Subnet Mask (Binary)
The first three octets of the address make up the network number (class C). You
want to have two separate networks.
N0115789
shows all possible subnet masks for a class C address using both
Subnet mask 1 Bits
/24
/25
/26
/27
/28
/29
/30
Network number
192.168.1.
11000000.10101000.00000001.
255.255.255.
11111111.11111111.11111111.
Last octet bit value
0000 0000
1000 0000
1100 0000
1110 0000
1111 0000
1111 1000
1111 1100
Host ID
0
00000000
0
00000000