Specifically, like in an IPv4 community, BIER can get the job done around L2 hyperlinks instantly or in excess of tunnels. Zheng Zhang, Bo Wu, Zhaohui Zhang, IJsbrand Wijnands, Yisong Liu, Hooman Bidgoli, 2022-07-03, This doc defines a BIER proxy operate to help a solitary BIER sub-area around multiple underlay routing protocol regions (Autonomous Systems or IGP locations).