IGMP Snooping（Internet Group Management Protocol Snooping）是运行 在二层以太网交换机上的组播约束机制，用于管理和控制组播组。 IGMP Snooping 运行在链路层。当二层以太网交换机收到主机和路由器之间 传递的IGMP 报文时，IGMP Snooping 分析IGMP 报文所带的信息。当监听 到主机发出的IGMP 主机报告报文（IGMP host report message）时，交换机 就将与该主机加入到相应的组播表中；当

BeagleBone Black Wireless is based on the extremely successful open-source hardware design of BeagleBone Black, a high-expansion, maker-focused, community-supported open hardware computer, created by the BeagleBoard.org Foundation. BeagleBone Blac