Would love to hear Cisco's thoughts about how or why something like NAC/ISE makes sense in a zero trust model? Doesn't that perpetuate the old "trusted network"design that zero trust is responding to? Zero trust is about authenticating the device and user as close to the service/data being accessed as possible. The access/network edge layer is where NAC/ISE live, so what role does an edge/access layer technology like that play in zero trust?