%% You should probably cite rfc3706 instead of this I-D.
@techreport{ietf-ipsec-dpd-04,
    number =    {draft-ietf-ipsec-dpd-04},
    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-ipsec-dpd/04/},
    author =    {Stephane Beaulieu and Geoffrey Huang and Dany Rochefort},
    title =     {{A Traffic-Based Method of Detecting Dead Internet Key Exchange (IKE) Peers}},
    pagetotal = 13,
    year =      2003,
    month =     oct,
    day =       23,
    abstract =  {This document describes the method detecting a dead Internet Key Exchange (IKE) peer that is presently in use by a number of vendors. The method, called Dead Peer Detection (DPD) uses IPSec traffic patterns to minimize the number of IKE messages that are needed to confirm liveness. DPD, like other keepalive mechanisms, is needed to determine when to perform IKE peer failover, and to reclaim lost resources. This memo provides information for the Internet community.},
}