Isolation of network traffic is essential to a secure ESXi environment. Different networks require different access and level of isolation.
Your ESXi host uses several networks. Use appropriate security measures for each network, and isolate traffic for specific applications and functions. For example, ensure that VMware vSphere vMotion® traffic does not travel over networks where virtual machines are located. Isolation prevents snooping. Having separate networks is also recommended for performance reasons.
vSphere infrastructure networks are used for features such as vSphere vMotion, VMware vSphere Fault Tolerance, and storage. Isolate these networks for their specific functions. It is often not necessary to route these networks outside a single physical server rack.
A management network isolates client traffic, command-line interface (CLI) or API traffic, and third-party software traffic from other traffic. This network should be accessible only by system, network, and security administrators. Use jump box or virtual private network (VPN) to secure access to the management network. Strictly control access within this network.
Virtual machine traffic can flow over one or many networks. You can enhance the isolation of virtual machines by using virtual firewall solutions that set firewall rules at the virtual network controller. These settings travel with a virtual machine as it migrates from host to host within your vSphere environment.