netmasks - DHCP server database
The netmasks file is employed by joind, the DHCP server, to inform it about any networks having non-standard subnet masks. This file is only needed on those platforms which don't provide a netmasks database, either as a text file or as an NIS map. Each network whose mask is other than the standard A, B, or C mask should have an entry in this file. Each entry has two fields: the network and the mask. The network may be written with or without zeros. See join.ipaddresses(4) for details.
This file also supports variable subnetting. If each subnetwork is further divided into subnetworks with a variable mask, the subnetworks can also appear on the LHS.
Blank lines and lines beginning with "#" are ignored. Entries are separated from one another by newlines. Entries consist of two fields: the network number (expressed as an IP address), and the network mask expressed as an IP address.
Commands: joind(8), join.ipaddresses(4). delim off