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Nobody on this thread really seems to be talking about one of the issues brought up in the IPv6 analysis (though I'm not sure if it caused their outages - any t
by ghshephard 12y ago
Nobody on this thread really seems to be talking about one of the issues brought up in the IPv6 analysis (though I'm not sure if it caused their outages - any time I read a post mortem with the phrase, "bridge loops" I usually don't look any further - that alone is enough to bring a network down)
If I read the post correctly, one of the roots of their problems seems to be that either (A) Traffic flooding causing excess traffic as a result of multicast packets being flooded over their network, or (B) If they used MLD snooping to reduce the flooding, the switches they have only support 3,000 entries for multicast groups - which are quickly exceeded with the privacy IPv6 addresses that are generated by the hosts (each of which creates it's own multicast entry, and some of their hosts had 10+ addresses)
Other than turning off privacy based IPv6 addresses, and moving to something like RFC 7217, is there a solution? Increasing the number of multicast entries on the switch to something larger, say, around 30,000 entries combined with reducing the length of time in which a privacy address is valid (and therefore requiring a group) from one day, to say, one hour?