%% You should probably cite rfc8950 instead of this I-D.
@techreport{ietf-bess-rfc5549revision-06,
    number =    {draft-ietf-bess-rfc5549revision-06},
    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-bess-rfc5549revision/06/},
    author =    {Stephane Litkowski and Swadesh Agrawal and Krishnaswamy Ananthamurthy and Keyur Patel},
    title =     {{Advertising IPv4 Network Layer Reachability Information (NLRI) with an IPv6 Next Hop}},
    pagetotal = 12,
    year =      2020,
    month =     sep,
    day =       1,
    abstract =  {Multiprotocol BGP (MP-BGP) specifies that the set of usable next-hop address families is determined by the Address Family Identifier (AFI) and the Subsequent Address Family Identifier (SAFI). The AFI/SAFI definitions for the IPv4 address family only have provisions for advertising a next-hop address that belongs to the IPv4 protocol when advertising IPv4 Network Layer Reachability Information (NLRI) or VPN-IPv4 NLRI. This document specifies the extensions necessary to allow the advertising of IPv4 NLRI or VPN-IPv4 NLRI with a next-hop address that belongs to the IPv6 protocol. This comprises an extension of the AFI/SAFI definitions to allow the address of the next hop for IPv4 NLRI or VPN-IPv4 NLRI to also belong to the IPv6 protocol, the encoding of the next hop to determine which of the protocols the address actually belongs to, and a BGP Capability allowing MP-BGP peers to dynamically discover whether they can exchange IPv4 NLRI and VPN-IPv4 NLRI with an IPv6 next hop. This document obsoletes RFC 5549.},
}