Identifies the Subnet Mask associated to the Internet Protocol Version 4 (IPv4) Address within the network interface device at a host or end user location.
VALID ENTRIES:
Subnet Mask Address
NOTE 1: An entry in this field must comply with the Internet Engineering Task Force (IETF) Standards for a Subnet Mask.
USAGE: This field is conditional.
NOTE 1: Required when the IP Address field is populated and the IPAI field is “4” or “M”, otherwise prohibited.
DATA CHARACTERISTICS: 15 alpha/numeric characters
EXAMPLE: 2 5 5 . 2 5 5 . 2 5 5 . 0