%% You should probably cite draft-ietf-radext-tunnel-type instead of this I-D.
@techreport{tiwari-radext-tunnel-type-02,
    number =    {draft-tiwari-radext-tunnel-type-02},
    type =      {Internet-Draft},
    institution =   {Internet Engineering Task Force},
    publisher = {Internet Engineering Task Force},
    note =      {Work in Progress},
    url =       {https://datatracker.ietf.org/doc/draft-tiwari-radext-tunnel-type/02/},
    author =    {Abhishek Tiwari},
    title =     {{New Tunnel-Type Values}},
    pagetotal = 6,
    year =      2008,
    month =     aug,
    day =       29,
    abstract =  {This document defines a set of values for the Tunnel-Type RADIUS Attribute.},
}