> From: int-area-boun...@ietf.org [mailto:int-area-boun...@ietf.org] On > Behalf Of Zhenghewen > Hi Thomas, > > In real world, some operator has 80 data centres in the > scope with the diameter of 1000KM, each data centre has average 1,500 > racks, each rack has average 20 servers, each servers has 20 VMs. That > means that there are up to 48millions MAC entries. Even only 20% VMs > generate traffic outside from local data centres, there are about 10M > MAC entries.
[snip] > Now, as we see, current FDB tables seem small, especially for cloud > data centre. Usually high-speed switch or router only has limited table > size, for example 128K or 512K MAC entries. > [snip] > Some solutions to solve the issue will be valuable [WEG] This is all very interesting theoretical math, but all it says to me is what we've known for years - L2 MAC domains don't scale infinitely - whatever the hardware capabilities, someone will come up with a theoretical case that exceeds it by many orders of magnitude. Several of us have said that the already extant solution is to shrink the L2 domain so that the number of MACs necessary to track is much smaller. Yes, RFC 6820 discusses some problems with that when it comes to VM mobility, but I'd argue that there are other solutions to those problems that start looking increasingly attractive at this sort of scale, including heavier use of DNS that is updated when a VM IP changes, etc. You need to explain why your proposed solution is less complicated than simply designing your VM infrastructure to be flexible enough that subnet changes don't break things. Wes George This E-mail and any of its attachments may contain Time Warner Cable proprietary information, which is privileged, confidential, or subject to copyright belonging to Time Warner Cable. This E-mail is intended solely for the use of the individual or entity to which it is addressed. If you are not the intended recipient of this E-mail, you are hereby notified that any dissemination, distribution, copying, or action taken in relation to the contents of and attachments to this E-mail is strictly prohibited and may be unlawful. If you have received this E-mail in error, please notify the sender immediately and permanently delete the original and any copy of this E-mail and any printout. _______________________________________________ Int-area mailing list Int-area@ietf.org https://www.ietf.org/mailman/listinfo/int-area
