Re: UDP multicast packets not seen on listening interface in BETA5

From: Josh Carroll (josh.carroll_at_gmail.com)
Date: 09/30/05

  • Next message: Josh Carroll: "[SOLVED] Re: UDP multicast packets not seen on listening interface in BETA5" 
    Date: Thu, 29 Sep 2005 21:24:22 -0700
To: freebsd-current@freebsd.org

    > Running tcpdump, unless you use the -p flag, will put the NIC into
    > promiscuous mode. This means you'll pick up all multicast frames
    > (and everything else) regardless of how the NIC's multicast filter is
    > programmed.

    > Just joining a group will not put the interface into promiscuous mode:
    > it'll just program the NIC's multicast filter to accept that particular
    > group. That is of course unless someone a) broke the driver for your
    > NIC or b) broke SIOCADDMULTI support somewhere in the stack. Until you
    > tell us what NIC you have, there's no easy way to tell which is the
    > case.

    Ok, tcpdump without -p shows the multicast packets, tcpdump with -p
    does not. Does that mean I have not joined the multicast group
    properly? Is this something that was fixed sometime after BETA3? This
    was working for a while in 5.4-RELEASE as well as since 6.0-BETA1.

    Josh
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  • Next message: Josh Carroll: "[SOLVED] Re: UDP multicast packets not seen on listening interface in BETA5"

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