vSphere Networking Design Decisions for the Management Domain

Use this design decision list for reference related to the configuration of the vSphere Distributed Switch instances and VMkernel adapters in a VMware Cloud Foundation environment.

The configuration tasks for most design decisions are automated in VMware Cloud Foundation. You must perform the configuration manually only for a limited number of decisions as noted in the design implication.

For full design details, see vCenter Server Design for the Management Domain.

Table 1. Design Decisions for vSphere Distributed Switch

Design ID	Design Decision	Design Justification	Design Implication
VCF-MGMT-VCS-VDS-001	Use a single vSphere Distributed Switch per cluster.	Reduces the complexity of the network design. Reduces the size of the fault domain.	Increases the number of vSphere Distributed Switches that must be managed.
VCF-MGMT-VCS-VDS-002	Configure the MTU size of the vSphere Distributed Switch to 9000 for jumbo frames.	Supports the MTU size required by system traffic types. Improves traffic throughput.	When adjusting the MTU packet size, you must also configure the entire network path (VMkernel ports, virtual switches, physical switches, and routers) to support the same MTU packet size.

Table 2. Design Decisions on Distributed Port Groups

Decision ID	Design Decision	Design Justification	Design Implication
VCF-MGMT-VCS-VDS-003	Use ephemeral port binding for the management port group.	Using ephemeral port binding provides the option for recovery of the vCenter Server instance that is managing the distributed switch.	Port-level permissions and controls are lost across power cycles, and no historical context is saved.
VCF-MGMT-VCS-VDS-004	Use static port binding for all non-management port groups.	Static binding ensures a virtual machine connects to the same port on the vSphere Distributed Switch. This allows for historical data and port level monitoring.	None.
VCF-MGMT-VCS-VDS-005	Use the Route based on physical NIC load teaming algorithm for the management port group.	Reduces the complexity of the network design and increases resiliency and performance.	None.
VCF-MGMT-VCS-VDS-006	Use the Route based on physical NIC load teaming algorithm for the vSphere vMotion port group.	Reduces the complexity of the network design and increases resiliency and performance.	None.

Table 3. Design Decisions on the vMotion TCP/IP Stack

Decision ID	Design Decision	Design Justification	Design Implication
VCF-MGMT-VCS-VDS-007	Use the vMotion TCP/IP stack for vSphere vMotion traffic.	By using the vMotion TCP/IP stack, vSphere vMotion traffic can be assigned a default gateway on its own subnet and can go over Layer 3 networks.	In the vSphere Client, the vMotion TCP/IP stack is not available in the wizard for creating a VMkernel network adapter wizard at the distributed port group level. You must create the VMkernel adapter directly on the ESXi host.

Table 4. Design Decisions on vSphere Network I/O Control

Decision ID	Design Decision	Design Justification	Design Implication
VCF-MGMT-VCS-VDS-008	Enable Network I/O Control on vSphere Distributed Switch of the management domain cluster	Increases resiliency and performance of the network.	If configured incorrectly, Network I/O Control might impact network performance for critical traffic types.
VCF-MGMT-VCS-VDS-009	Set the share value for management traffic to Normal.	By keeping the default setting of Normal, management traffic is prioritized higher than vSphere vMotion but lower than vSAN traffic. Management traffic is important because it ensures that the hosts can still be managed during times of network contention.	None.
VCF-MGMT-VCS-VDS-010	Set the share value for vSphere vMotion traffic to Low.	During times of network contention, vSphere vMotion traffic is not as important as virtual machine or storage traffic.	During times of network contention, vMotion takes longer than usual to complete.
VCF-MGMT-VCS-VDS-011	Set the share value for virtual machines to High.	Virtual machines are the most important asset in the SDDC. Leaving the default setting of High ensures that they always have access to the network resources they need.	None.
VCF-MGMT-VCS-VDS-012	Set the share value for vSAN traffic to High.	During times of network contention, vSAN traffic needs a guaranteed bandwidth to support virtual machine performance.	None.
VCF-MGMT-VCS-VDS-013	Set the share value for other traffic types to Low.	By default, VMware Cloud Foundation does not use other traffic types, like vSphere FT traffic. Hence, these traffic types can be set the lowest priority.	None.