Unable to access vCenter with 404 error

Products

• VMware vCenter Server

Issue/Introduction

• vCenter deploys without issue however when accessing vCenter from a system on a different subnet or network there is a 404 error.
• Access to vCenter from a system on the same subnet and network is successful.  

Environment

• vCenter 7.x
• vCenter 8.x
• vCenter 9.x

Cause

This is a network configuration issue and is external to VMware.

Resolution

• Reference VMware Ports and Protocols and open any ports that are closed between the system and vCenter.
• Verify network configuration allows traffic between the subnets.