Overview of vNetwork Distributed Switch concepts

Products

• VMware vCenter Server
• VMware vSphere ESXi

Issue/Introduction

There are two types of virtual switches in ESXi; virtual Standard Switch and virtual Distributed Switch (vDS).

Environment

VMware vSphere
VMware ESXi 

Resolution

vNetwork Standard Switch (vSwitch, vSS)

The configuration of each standard switch resides on the specific ESXi/ESX host. The vSphere administrators have to manually maintain consistency of the standard vSwitch configuration across all ESXi/ESX hosts to ensure that they can perform operations such as vMotion. (Switch and Portgroup names must be identical)

vSwitches are configured independently on each ESXi/ESX host.
 

vNetwork Distributed Switch (dvSwitch, vDS)

The configuration of vDS is centralized to vCenter Server. The ESXi hosts that belong to a dvSwitch do not need further configuration to be compliant.

Distributed switches provide similar functionality to vSwitches. dvPortgroups is a set of dvPorts. The vDS equivalent of portgroups is a set of ports in a vSwitch. Configuration is inherited from dvSwitch to dvPortgroup, just as from vSwitch to Portgroup.

Virtual machines, Service Console interfaces (vswif), and VMKernel interfaces can be connected to dvPortgroups just as they could be connected to portgroups in vSwitches.

Administrative rights are required to create these virtual adapters on each ESXi/ESX host dvSwitch in vCenter Server:

• Service Console and VMKernel interfaces
• Physical NICs and their assignment to dvSwitch Uplink groups

For more information on configuring a dvSwitch in vCenter 7.0, see vSphere 7.0 Networking Guide.
For more information on configuring a dvSwitch in vCenter 8.0, see vSphere 8.0 Networking Guide.

Comparing vNetwork Standard Switch with vNetwork Distributed Switch

These features are available with both types of virtual switches:

• Can forward L2 frames
• Can segment traffic into VLANs
• Can use and understand 802.1q VLAN encapsulation
• Can have more than one uplink (NIC Teaming)
• Can have traffic shaping for the outbound (TX) traffic

These features are available only with a Distributed Switch:

• Can shape inbound (RX) traffic
• Has a central unified management interface through vCenter Server
• Supports Private VLANs (PVLANs)
• Provides potential customization of Data and Control Planes

vSphere 5+ provides these improvements to Distributed Switch functionality:

• Increased visibility of inter-virtual machine traffic through Netflow.
• Improved monitoring through port mirroring (dvMirror).
• Support for LLDP (Link Layer Discovery Protocol), a vendor-neutral protocol.
• The enhanced link aggregation feature provides choice in hashing algorithms and also increases the limit on number of link aggregation groups.
• Additional port security is enabled through traffic filtering support.
• Improved single-root I/O virtualization (SR-IOV) support and 40GB NIC support.

vSphere 6+ provides these improvements to Distributed Switch functionality:

• Network IO Control – New support for per virtual machine Distributed vSwitch bandwidth reservations to guarantee isolation and enforce limits on bandwidth.
• Multicast Snooping - Supports IGMP snooping for IPv4 packet and MLD snooping for IPv6 packets in VDS. Improves performance and scale with multicast traffic.
• Multiple TCP/IP Stack for vMotion - Allows vMotion traffic a dedicated networking stack. Simplifies IP address management with a dedicated default gateway for vMotion traffic.

 

Additional Information

• The Distributed Switch overview on the VMware vSphere product site
• This VMware VROOM! Blog Improvements in Network I/O Control for vSphere 6
  
  Note: vDS now comes bundled with NSX for vSphere (NSXv) and VMware vSAN in vSphere 6.x.