%% You should probably cite rfc2473 instead of this I-D.
@techreport{ietf-ipngwg-ipv6-tunnel-07,
    number =    {draft-ietf-ipngwg-ipv6-tunnel-07},
    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-ipngwg-ipv6-tunnel/07/},
    author =    {Dr. Steve E. Deering and Alex Conta},
    title =     {{Generic Packet Tunneling in IPv6 Specification}},
    pagetotal = 36,
    year =      1996,
    month =     dec,
    day =       23,
    abstract =  {This document defines the model and generic mechanisms for IPv6 encapsulation of Internet packets, such as IPv6 and IPv4. {[}STANDARDS-TRACK{]}},
}