%% You should probably cite draft-ietf-pim-rfc4601bis instead of this I-D.
@techreport{parekh-pim-rfc4601bis-01,
    number =    {draft-parekh-pim-rfc4601bis-01},
    type =      {Internet-Draft},
    institution =   {Internet Engineering Task Force},
    publisher = {Internet Engineering Task Force},
    note =      {Work in Progress},
    url =       {https://datatracker.ietf.org/doc/draft-parekh-pim-rfc4601bis/01/},
    author =    {Hugh Holbrook and Rishabh Parekh and Isidor Kouvelas and Mark J. Handley and Lianshu Zheng and Bill Fenner (ˢˣˠ)},
    title =     {{Protocol Independent Multicast - Sparse Mode (PIM-SM): Protocol Specification (Revised)}},
    pagetotal = 132,
    year =      2011,
    month =     jul,
    day =       7,
    abstract =  {This document specifies Protocol Independent Multicast - Sparse Mode (PIM-SM). PIM-SM is a multicast routing protocol that can use the underlying unicast routing information base or a separate multicast- capable routing information base. It builds unidirectional shared trees rooted at a Rendezvous Point (RP) per group, and optionally creates shortest-path trees per source. This document addresses errata filed against RFC 4601, and removes the optional (*,*,RP) feature that lacks sufficient deployment experience.},
}