The Local Peer Discovery protocol, specified as BEP-14, is an extension to the BitTorrent file-distribution system. It is designed to support the discovery of local BitTorrent peers, aiming to minimize the traffic through the Internet service provider's (ISP) channel and maximize use of higher-bandwidth local area network (LAN).
Local Peer Discovery is implemented with HTTP-like messages on User Datagram Protocol (UDP) multicast group 239.192.152.143:6771 (IPv4) or ff15::efc0:988f (IPv6) which are administratively scoped multicast addresses. Since implementation is simple, Local Peer Discovery is implemented in several clients (μTorrent, BitTorrent/Mainline, MonoTorrent, libtorrent and its derivatives, Transmission, aria2). An alternative multicast peer discovery protocol is published as BEP 26, but is not widely adopted since it is considered too complex in comparison.