%% You should probably cite rfc5566 instead of this I-D.
@techreport{ietf-softwire-encaps-ipsec-03,
    number =    {draft-ietf-softwire-encaps-ipsec-03},
    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-softwire-encaps-ipsec/03/},
    author =    {Russ White and Eric C. Rosen and Lou Berger},
    title =     {{BGP IPsec Tunnel Encapsulation Attribute}},
    pagetotal = 8,
    year =      2009,
    month =     apr,
    day =       6,
    abstract =  {The BGP Encapsulation Subsequent Address Family Identifier (SAFI) provides a method for the dynamic exchange of encapsulation information and for the indication of encapsulation protocol types to be used for different next hops. Currently, support for Generic Routing Encapsulation (GRE), Layer 2 Tunneling Protocol (L2TPv3), and IP in IP tunnel types are defined. This document defines support for IPsec tunnel types. {[}STANDARDS-TRACK{]}},
}