Consistency check to see if node and switch agree on the mac address provided when registering

[naved001]

When we register a nic on a node, we type in the mac address without checking to see if the port on the switch expects that mac address. Though not required, it could be a good safety check.
This came up in a discussion with Chris Hill.

@SahilTikale @henn

[SahilTikale]

I feel this is a good reliability check. We should have this call that verifies that nodes are connected to correct ports and via the mac addresses that administrators thinks were right. This is a good way to reduce dependency on a single human input and reduce chances of error.

[naved001]

so when do we want to do this check? right when we are registering a NIC?

[henn]

I like it, as long as there's an override to the check in case we're setting up a port before the machine is connected.

Possible complications could be caused by additional MAC addresses due to bridged VMs/containers or BMCs. This would likely mean verifying that a MAC address is in a list of addresses.