Type the Network Mask to use to allow access.
The network mask, combined with the IP address, identifies the subnetwork for the HMC location.
If you do not know or are not sure of the HMC IP address/network mask, contact your network or system administrator.
The network mask is a 32-bit dotted-decimal
number indicating the range of IP addresses residing on a single
IP network/subnet/supernet.
It must be specified in the format
nnn.nnn.nnn.nnn:
where nnn is specified as zero (0), 128, 192, 224, 240, 248, 252, 254 or, 255.
Additionally, if nnn is specified as a value other than 255, each number to the right of it, if any, must be zero (0). For example: 255.255.255.0