Re: [armd] address resolution requirement from hosts to overlay edge nodes. Any opinion?

[Mike McBride <[e-mail]>]

Anoop,

On Tue, Feb 14, 2012 at 12:32 PM, Anoop Ghanwani <[e-mail]> wrote:
> On Tue, Feb 14, 2012 at 12:14 PM, Mike McBride <[e-mail]> wrote:
>> And what protocol improvements are needed for multicast with overlays?
>> The multicast community is ready to help. Multicast makes us happy. Or
>> are you solely talking about vendor implementation, s/w release, hw
>> support problems? AFAIK multicast works fairly well with VXLAN, TRILL,
>> L2VPN... What's missing?
>
> The whole problem of sending L2 multicast over a campus or data center
> backbone, in any sort of significant way, is a new one enabled for the first
> time by overlays.  There are interesting challenges when pushing large
> amounts of multicast traffic through a network, and  have thus far been dealt
> with using purpose-built networks.  While the overlay proposals have
> been careful not to impose new protocol requirements, they have not
> addressed the issues of performance and scalability, nor the large-scale
> availability of these protocols.

There are interesting challenges with unicast and multicast in big
flat DC networks. That's why we are here. One of the constant themes
we hear with multicast is the FUD that it doesn't scale. Especially
from vendors who are pushing another solution or who have a crappy
multicast implementation. Meanwhile multicast is being deployed in
large scale networks without scaling issue. Large L2 overlay networks?
I don't know. Would be good to find out from the community about
performance and scalability of multicast in the DC.

mike