On Wed, 2013-01-30 at 09:39 +0200, Jussi Peltola wrote: > High density virtual machine setups can have 100 VMs per host.
OK, I see where you are coming from now. Hm. If you have 100 VMs per host and 48 hosts on a switch, methinks you should probably invest in the finest switches money can buy, and they will have no problem tracking that state. While it is certainly a hefty dose *more*, it is geometrically, not exponentially more, so not a scalability issue IMHO. An ordinary old IPv4 switch tracks 4800 L2/port mappings in the scenario you describe. If each VM had just two addresses, it would be 9600... I wonder if there is hard information out there on how many multicast groups a modern switch can actually maintain in this regard. Are you saying you have seen actual failures due to this, or are you supposing? Serious question - is this a possible problem or an actual problem? > multicast groups - some virtual hosters give /64 per VM, which brings > about all kinds of trouble not limited to multicast groups if the client > decides to configure too many addresses to his server. There is always some way to misconfigure a network to cause trouble. It's a bit unfair to make that IPv6's fault. As a matter of interest, what is the "all kinds of trouble" that a client can cause by configuring too many addresses on their server? Things that are not the client-side problems, obviously ;-) Regards, K. -- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Karl Auer (ka...@biplane.com.au) http://www.biplane.com.au/kauer http://www.biplane.com.au/blog GPG fingerprint: B862 FB15 FE96 4961 BC62 1A40 6239 1208 9865 5F9A Old fingerprint: AE1D 4868 6420 AD9A A698 5251 1699 7B78 4EEE 6017
