SDN overlay · the table that disambiguates

Dashed = logical IP · what the VM sees
Solid = physical · SDN layer only

What the VM sees — just the logical IP

VPC · vpc-a
web10.0.0.5
VPC · vpc-b
web10.0.0.5

SDN layer · hidden from the tenant

mapping table · (VPC, logical IP) → physical host

VPC
logical IP
physical host
vpc-a
10.0.0.5
10.51.0.7
vpc-b
10.0.0.5
10.51.0.9

packet on the wire · vpc-a's 10.0.0.5

outer · dst 10.51.0.7 (physical host, from table)
inner · dst 10.0.0.5 (vpc-a, what the VM sent)
payload

The full descent — where addressing bottoms out

overlay10.0.0.5logical · what the VM sees
mapping service / Andromeda · encapsulate
substrate10.51.0.7physical host · the cloud's own fabric (real, routable here)
ARP
linkMAC → switch portcopper / fiber · stops here — no third IP