[c-nsp] Multihomed OTV on CSR Lab - Mac Address Issue

[adamv0025 at netconsultings.com]

> From: Aaron Gould [mailto:aaron1 at gvtc.com]
> Sent: Thursday, February 01, 2018 5:05 PM
> 
> So I think (I could be wrong as I'm not a server guy) that all this L2
network
> emulation is because of server virtualization and moving vm's or vmotion
or
> something like that, and that they need to be in same ip subnet (aka bcast
> domain).... correct ?
> 
> *if* that's true, and *if* all this layer 2 networking madness is because
of
> that point stated above, I would think that someone (vendors/standards
> bodies/companies) would/should be working really hard to make that server
> stuff work in different bcast domains (different subnets)...so we wouldn't
> have to do all that L2 stuff
> 
Well there are attempts but I think it might actually need the whole IPv6
shebang to take off till these become BAU.

Oh and I'd like to correct myself actually I listed VPWS as one of the
technologies created for DCI but that's not true as it was developed well
before DCI was a thing, to transport anything over MPLS hence the AToM. 
There's an interesting story about these L2 overlay circuits actually, seems
like they have been around since ever. 
(Anyone here that remembers SNA over DLSW and SDLC on serial interface to
mainframe?)
When I started in networking I was setting up p2p leased lines between
csu/dsu boxes (t-shooting fractional T1s and stuff on DSX cross-connects).
Then we were migrating these to FR or ATM circuits. And then we were
migrating FR/ATM to MPLS cause MPLS was any to any. And heck couple years
later there are requests from customers to go back to these p2p circuits
(using PW over MPLS) to close the circle. 
So back in the days it could happen that the links between MPLS devices
where set up over FR network(which in itself was built on top of these
leased lines) and you'd have customers being migrated off of the very same
FR network to MPLS just to ask for the same setup they have with FR i.e. hub
and spoke p2p links and own IP routing, so what they got at the end was
product based on VPWS.
This was before the Carrier Ethernet became a thing -where we sell p2p
Ethernet links for SPs to build their MPLS backbones on top and don't need
to lease, well not T1s but fibre/lambdas. 
So here we are, couple years and overlay headers later still doing the same
thing. 

adam