We require NIST 800-171 compliance and one of the changes we have to make is for the VM network to be on a different VLAN than the management network. When I tried to change the VLAN ID of the VM network, it took all the VMs offline until I changed it back. What am I doing wrong? I have attached our vSwitch topology.
The VLAN range is 1-4094
in the image you have assigned VLAN = 0 ...that is, you have disabled the VLANs
How did you configure the vlans on the physical Switch?
this link may be useful to you:
How does the physical switch ports' configuration look like?
You cannot just tag VLAN traffic on one side (e.g. virtual), and expect the other side (e.g. physical) to understand/accept the traffic.