The /etc/inet/netmasks File

If your network runs NIS or NIS+, the servers for these name services maintain netmasks databases. For networks that use local files for name service, this information is maintained in the /etc/inet/netmasks file.

For compatibility with BSD-based operating systems, the file /etc/netmasks is a symbolic link to /etc/inet/netmasks.

The following example shows the /etc/inet/netmasks file for a class B network.

Example 7-3 /etc/inet/netmasks File for a Class B Network

## The netmasks file associates Internet Protocol (IPv4) address
 # masks with IPv4 network numbers.
 #
 # 	network-number	netmask
 #
 # Both the network-number and the netmasks are specified in
 # "decimal dot" notation, e.g:
 #
 #        128.32.0.0   255.255.255.0
 129.144.0.0  255.255.255.0

If the file does not exist, create it. Use the following syntax:

network-number	netmask-number

Refer to the netmasks(4) man page for complete details.

When creating netmask numbers, type the network number assigned by the InterNIC (not the subnet number) and netmask number in /etc/inet/netmasks. Each subnet mask should be on a separate line.

For example:

128.78.0.0	    255.255.248.0

You can also type symbolic names for network numbers in the /etc/inet/hosts file. You can then use these network names instead of the network numbers as parameters to commands.