Note: The important things that need to remember about VMkernel!
The VMkernel networking layer provides connectivity to hosts and handles the standard system traffic of vSphere vMotion, IP storage, Fault Tolerance, vSAN, and others. You can also create VMkernel adapters on the source and target vSphere Replication hosts to isolate the replication data traffic.
TCP/IP Stacks at the VMkernel Level
- Default TCP/IP stack – Provides networking support for the management traffic between vCenter Server and ESXi hosts, and for system traffic such as vMotion, IP
storage, Fault Tolerance, and so on.
- vMotion TCP/IP stack – Supports the traffic for live migration of virtual machines. Use the vMotion TCP/IP to provide better isolation for the vMotion traffic. After you create a VMkernel adapter on the vMotion TCP/IP stack, you can use only this stack for vMotion on this host. The VMkernel adapters on the default TCP/IP stack are disabled for the vMotion service. If a live migration uses the default TCP/IP stack while you configure VMkernel adapters with the vMotion TCP/IP stack, the migration completes successfully. However, the involved VMkernel adapters on the default TCP/IP stack are disabled for future vMotion sessions.
- Provisioning TCP/IP – stack Supports the traffic for virtual machine cold migration, cloning, and snapshot migration. You can use the provisioning TCP/IP to handle Network File Copy (NFC) traffic during long-distance vMotion. NFC provides a file-specific FTP service for vSphere. ESXi uses NFC for copying and moving data between datastores. VMkernel adapters configured with the provisioning TCP/IP stack handle the traffic from cloning the virtual disks of the migrated virtual machines in long-distance vMotion. By using the provisioning TCP/IP stack, you can isolate the traffic from the cloning operations on a separate gateway. After you configure a VMkernel adapter with the provisioning TCP/IP stack, all adapters on the default
TCP/IP stack is disabled for the Provisioning traffic.
- Custom TCP/IP stacks – You can add custom TCP/IP stacks at the VMkernel level to handle networking traffic of custom applications.