vSphere vMotion recommended networking best practices.

Migration with vMotion requires correctly configured network interfaces on source and target hosts.

Configure each host with at least one vMotion network interface. vMotion network traffic is not encrypted. You should provision secure private networks for use by vMotion only. Because vMotion performance shows great improvement with additional bandwidth, dedicate at minimum a physical 1 Gigabit Ethernet (GigE) Network Interface Card (NIC) to vMotion. As a best practice, provision at least one additional physical NIC as a failover NIC.

vSphere vMotion:

• Use one dedicated GigE adapter for vMotion. Consider using a 10 GbE vMotion network. Using a 10 GbE network in place of a 1 GbE network for vMotion results in significant improvements in vMotion performance. When using large virtual machines (for example, 64GB or more), consider using multiple 10 GbE network adapters for vMotion to further improve vMotion performance.
• If only two Ethernet adapters are available:
  • For best security, dedicate the GigE adapter to vMotion, and use vLANs to divide the virtual machine and management traffic on the other adapter.
  • For best availability, combine both adapters into a bond, and use vLANs to divide traffic into networks; one or more for virtual machine traffic and one for vMotion.
• If your networking infrastructure constrains and you must have multiple traffic flows (for example, virtual machine traffic and vMotion traffic) sharing the same set of network adapters, use the vSphere Network I/O Control (NetIOC) feature to partition the network bandwidth allocation among the different traffic flows.
• On each host, configure a VMkernel port group for vMotion.
• Ensure that virtual machines have access to the same subnets on source and destination hosts.
• If you are using standard switches for networking, ensure that the network labels used for virtual machine port groups are consistent across hosts. During a migration with vMotion, vCenter Server assigns virtual machines to port groups based on matching network labels.
• If you are using vSphere Distributed Switches for networking, ensure that source and destination hosts are members of all vSphere Distributed Switches that virtual machines use for networking.
• Use of Jumbo Frames is recommended for the best vMotion performance.
• To determine the maximum number of concurrent vMotions possible, see the Concurrent migration limits at vCenter Server Limits on Simultaneous Migrations . These limits vary with a host's link speed to the vMotion network.

References: VMware vSphere 8.0 Documentation