I'll admit, I ran into this by accident. But now that I know how and why it works, it makes perfect sense.
There are multiple places to enable the sharing of a network
- During the configuration of an Organization vDC when a new vShield Edge Gateway and Organization Routed External Network are created.
- Viewing the Properties of an Organization Network, including Organization External Direct, Organization Routed External, and Isolated
- During the configuration of a new Organization Network, including Organization External Direct, Organization Routed External, and Isolated
You will see a box that looks like this:
As we can see in this screen shot, we have shared 2 Org Networks from this Org vDC
OK, the network is shared to other Organization vDCs, but where is it? If you have multiple Provider vDCs, then the network will ONLY be visible if the Organization vDC is backed by the same Provider vDC. Here is a screenshot of another Organization vDC that is backed by the same Provider vDC. The two networks being shared are backed by the original Organization vDC.
If we look at another Organization vDC that is backed by a separate Provider vDC as well as separate vCenter instance, the network cannot be seen. (NOTE: i have not tested this with two clusters owned by the same vCenter. It may work because VXLAN only works between a single vCenter and vShield Manager instance. This demonstration is showing between 2 Provider vDCs being presented by 2 vCenters. If both clusters were owned by the same vCenter, it might work)
So what's the point of doing this? If an application lives within an Organization vDC that has a Reservation or Allocation Pool set as the Allocation Model it may or may not have enough room to run more VMs. Therefore, you could create a secondary Org vDC with Pay-as-you-Go and run more VMs on that network on a temporary basis. Do you have any more ideas on why to share networks? Feel free to share.