Onload User Guide (UG1586)

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1.2 English

For an accelerated socket, Onload will usually behave as if IP_MULTICAST_ALL=0. However:

  • If two multicast sockets are bound to INADDR_ANY:<same_port> in different stacks, then Onload does behave as if IP_MULTICAST_ALL=0. But if the sockets are in one stack, then they both receive all packets, as if IP_MULTICAST_ALL=1.

    The behavior is even more complex if the sockets join the same address on different VLANs.

  • There is always the potential for messages to arrive at the host - perhaps from an unsupportedsupportedinterface or via the loopback interface - which will also be delivered to the socket under normal UDP port matching rules so the socket could receive traffic for groups not explicitly joined on this socket.