You receive the following error in SCVMM when assigning a vNIC to a logical switch on a host.
No MAC addresses were available to allocate to network adapter (<name here>).
Allocate additional MAC address pools and retry the operation.
I checked the pool using Get-SCStaticIPAddressPool and sure enough there are IP’s still available:
What do you do? If you manually try to assign a MAC, it bombs out with the error 25270. So! Recreate the vNIC to fix the issue.