can a network interface join multiple groups [closed]

Closed. This question i开发者_Go百科s off-topic. It is not currently accepting answers.

---

Want to improve this question? Update the question so it's on-topic for Stack Overflow.

Closed 11 years ago.

Improve this question

when i talk about ip multicasting, we know it is possible that:

1. one or more processes can join the same group on the same interface
2. one or more interfaces can join the same group

my question is that is it possible for one interface to join multiple groups so that it can send or receive different groups multicast

---

Yes. IP multicasting is at a higher-level than NICs. The NIC just knows about ethernet multicast, and doesn't care about IP or IGMP.

NICs usually support multicast filters, you can add up to a certain number of multicast ethernet addresses that the NIC should listen for. Once you surpass that limit, the only way to listen to more multicast addresses is to put the NIC in promiscuous mode, with the performance degradation that may entail on a busy network.