What are the VMkernel TCP/IP Stacks?
Today, I would like to take a deeper look at the VMkernel TCP/IP stacks with you.
As you might know, the VMkernel networking stack handles standard system traffic to hosts. This includes, but is not limited to vSphere vMotion, vSphere FT, vSphere HA and VSAN.
When talking about different VMkernel TCP/IP stacks, VMware differentiates between 3 major TCP/IP stacks:
- Default TCP/IP stack
- vMotion TCP/IP stack
- Provisioning TCP/IP stack
Let’s take a look at the details of each TCP/IP stack:
Default TCP/IP stack
Management traffic between ESXi hosts and vCenter server are considered as the default TCP/IP stack. Also, host related traffic like vMotion, NFS/iSCSI storage, HA and vSphere FT are part of it.
vMotion TCP/IP stack
By creating a VMkernel port on the vMotion TCP/IP stack you can isolate vMotion traffic to this stack. By doing so, vMotion traffic will be disabled on the default TCP/IP stack. The vMotion TCP/IP stack is used for live VM migrations.
VMware recommends configuring a separate vMotion TCP/IP stack and isolate management traffic from vMotion traffic.
Provisioning TCP/IP stack
The provisioning TCP/IP stack is used for cold VM migration, cloning and snapshotting traffic. In case of a long-distance vMotion (new in vSphere 6), NFC traffic can be configured to use the provisioning TCP/IP stack. Setting up a provisioning TCP/IP stack is useful when you want to isolate this traffic from other TCP/IP stacks. A dedicated provisioning TCP/IP stack is common in VDI environments and in setups with frequent VM snapshots.
Configuring a Distributed Switch can be a pain, especially if you do it for the first time after using a virtual switch. A virtual switch is mostly used in smaller environment with only a few ESXi hosts. Once you expand into 10+ ESXi hosts, you want to use a Distributed Switch to cut down the time it takes to configure an ESXi host and enhance the manageability of the ESXi networking component.
