service discovery and often don’t need
multicast. Because the leverage point
is at the edge, the dynamic changes
completely; and because the semantics
are now more interesting at the edge,
you have a clash of paradigms.
neaSe: We’ve seen the same process
take place with blade servers. When
we started centralizing some of the
functions that used to be distributed
among many servers, we could easily
and authoritatively know things that
used to be difficult to obtain. Things—
for example, in station state, address,
or user—became much easier to deter-
mine because the new blade architec-
ture made it very convenient.

caSaDo: Most scalable clouds are sub-networked. They are architected to not deal with VLANs (virtual LANs) or do flat anything and are not going to try and do one big L2 domain. It’s all subnet’ed upfront with the cloud overlaid on top.

Networks do not have virtualization
built in, and VLANs are not virtualiza-
tion in a global sense. It’s easier just to
treat the entire network infrastructure
as a big dumb switch and hold the in-
telligence at the edge because that is
where the semantics are.