为了使Udp组播正常工作，路由器必须支持它吗?
问题描述：
我想知道udp多播能否正常工作，路由器必须支持吗?
I am wondering for the udp multicast to work, router must support it?
答
多播基于动态生成的树，这些树可以(理论上)跨越整个Internet.这些多播树基于两种协议:
Multicast is based on dynamically generated trees that can (theoretically) span the entire internet. These multicast trees are based on two protocols:
- IGMP :Internet组管理协议.由像我和您这样的接收者和用户使用.
- PIM :协议无关的组播.路由器用来相应地复制和重新路由数据包.
- IGMP: Internet Group Management Protocol. Used by receivers and users like me and you.
- PIM: Protocol Independent Multicast. Used by routers to replicate and reroute the packets accordingly.
客户端必须与IGMP兼容，而路由器也必须与PIM兼容.
The client needs to be IGMP-compatible, and the routers need to be PIM-compatible.