ZyXEL Communications ZyWall 10 Reference Manual page 54

ZyWALL 10~100 Series Internet Security Gateway
NO. "BORROWED" HOST BITS
9
10
11
12
13
14
15
8-8
Chart 8-13 Class B Subnet Planning
SUBNET MASK
255.255.255.128
(/25)
255.255.255.192
(/26)
255.255.255.224
(/27)
255.255.255.240
(/28)
255.255.255.248
(/29)
255.255.255.252
(/30)
255.255.255.254
(/31)
NO. SUBNETS NO. HOSTS PER SUBNET
512
1024
2048
4096
8192
16384
32768
126
62
30
14
6
2
1
IP Subnetting