If you want to install vCenter Server with an externalPlatform Services Controller in an environment with multiple NICs, you must keep a record of the IP addresses or FQDNs that you use as system network names.
For example, if you want to install a Platform Services Controller on one virtual machine and vCenter Server on another virtual machine and each virtual machine has two NICs, you can use the following workflow:
Install a Platform Services Controller one of the virtual machines and use one of its IP addresses or FQDNs as a system network name.
On the other virtual machine, start the installation of vCenter Server and use one of its IP addresses or FQDNs as a system network name.
When prompted to provide the system network name of the Platform Services Controller, enter the IP address or FQDN that you entered during the installation of the Platform Services Controller.
If you enter the other IP address or FQDN of the Platform Services Controller, you receive an error message.
After the installation completes, you can log in to the vSphere Web Client by using either of the NIC IP addresses or FQDNs of vCenter Server.