http://www.rfc-editor.org/rfc/rfc1877.txt
RFC 1877: PPP Internet Protocol Control Protocol Extensions for Name Server Addresses, S. Cobb1995-12-01T23:00:00-00:00This document extends the NCP for establishing and configuring the Internet Protocol over PPP [2], defining the negotiation of primary and secondary Domain Name System (DNS) [3] and NetBIOS Name Server (NBNS) [4] addresses. This memo provides information for the Internet community. This memo does not specify an Internet standard of any kind.