IGMP (v3) older version querier timer on OSX

[brandon at burn.net (Brandon Applegate)]

First of all - if there is a better place to ask this, let me know.  I simply want to make sure the audience has the technical chops to try to answer the question.  So discussions.apple.com / macrumors are out.

Iâ??m trying to figure out how OSX is behaving with regard to downgrading sent IGMP messages in the presence of â??olderâ?? queriers.  I.e. if a query is heard from a router (querier) that is v2, start a timer and only speak (IGMP) in v2 until it expires.  From the definitions Iâ??ve found of how to calculate this timer - that should be 260 seconds.  After this time, assuming we havenâ??t heard any further v2 queries - we can start speaking v3 again.  From my testing (using 10.9 Mavericks and the newest VLC) - this doesnâ??t happen.  From the network side, Iâ??m using a Cisco 3750 with snooping and querier turned on (i.e. not a real mcast router).

If I turn these off and reboot, VLC causes IGMP v3 to be sent.  If I turn querier back on on my switch - OSX drops down to IGMP v2.  It just never seems to bounce back to v3.  I think I waited ~ 10 minutes on my last test, and it was still v2.

Thanks - and sorry this isnâ??t about systemd (although I am reading the thread and think itâ??s a great topic).

--
Brandon Applegate - CCIE 10273
PGP Key fingerprint:
830B 4802 1DD4 F4F9 63FE  B966 C0A7 189E 9EC0 3A74
"SH1-0151.  This is the serial number, of our orbital gun."

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 842 bytes
Desc: Message signed with OpenPGP using GPGMail
URL: <http://mailman.nanog.org/pipermail/nanog/attachments/20141024/92c7d807/attachment.pgp>