%% You should probably cite rfc1334 instead of this I-D.
@techreport{ietf-pppext-authentication-06,
    number =    {draft-ietf-pppext-authentication-06},
    type =      {Internet-Draft},
    institution =   {Internet Engineering Task Force},
    publisher = {Internet Engineering Task Force},
    note =      {Work in Progress},
    url =       {https://datatracker.ietf.org/doc/draft-ietf-pppext-authentication/06/},
    author =    {William A. Simpson},
    title =     {{PPP Authentication Protocols}},
    pagetotal = 16,
    year =      1992,
    month =     aug,
    day =       26,
    abstract =  {This document defines two protocols for Authentication: the Password Authentication Protocol and the Challenge-Handshake Authentication Protocol. {[}STANDARDS-TRACK{]}},
}