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

VMotion requires a Gigabit Ethernet (GigE) network between all VMotion-enabled hosts. Each host enabled for VMotion must have a minimum of two Ethernet adapters, at least one of which must be a GigE adapter.

Recommended networking best practices are as follows:

Use one dedicated Ethernet adapter for the service console (on ESX hosts).

Use one dedicated GigE adapter for VMotion.

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, one for the service console (on ESX hosts), and one for VMotion.

Configure the virtual networks on VMotion-enabled hosts as follows:

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.

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.

Use of Jumbo Frames is recommended for best VMotion performance.