WHAT IS VIRTUAL SWITCH ?
A VMware Virtual Switch is Layer-2 Switch embedded in VMkernel itself. It’s a software switch runs under the control of the ESXi Hypervisor and responsible for providing all network-based communications with and within an ESXi Host System.
It’s a virtual network living inside ESX Kernel providing interconnectivity between VMs and the external physical Network via Standard Networking Protocols.
TYPE OF COMMUNICATIONS SUPPORTED BY VIRTUAL SWITCH
- Virtual Machine Communications running on same ESXi Host
- Virtual Machine Communications running on different Hosts via Physical Network
- VMkernel Network Traffic
- vMotion Network Traffic across hosts
- IP Storage Traffic ( NFS & iSCSI)
- ESXi Management Traffic
- Fault Tolerance Traffic between Hosts
KEY FUNCTIONALITIES OF VIRTUAL SWITCH
- It’s a core Layer-2 Forwarding Engine which forwards traffic based on MAC Layer Addresses.
- It maintains MAC address and Port Forwarding Table.
- It does Forwarding and Filtering of Ethernet Frames like Physical Switch & avoid unnecessary broadcast ( in other words, it is not a hub)
- Similar to Physical Switch, when a frame is received on an Interface, the switch looks at the destination hardware address and finds the exit interface in the MAC Table. The Frame is only forwarded to Specified Destination Port. It does Unicast Communication.
- It also supports VLAN segmentation at the port level and supports Access and Trunk Mode.
- It enables many VMs to share same Physical NIC and Communicate directly with each other.
HOW VIRTUAL SWITCH IS DIFFERENT FROM PHYSICAL SWITCH
- ESX provides direct channel for configuration information such as MAC address updates from vNIC adapters so no need to learn MAC address.
- vSwitch doesn’t do MAC address learning since vNIC adapters resides in VMkernel itself.
- There is no way to interconnect multiple virtual switches, thus the network can’t be configured to introduce loops. As a result, Spanning Tree Protocol ( STP ) is not needed and not present.
- Traffic received on an uplink is never forwarded to another uplink.
- vSwitches can’t share physical NICs.
- No provisioning of cascading vSwitches – Capability is not provided.
- Network Traffic can’t flow directly from one virtual switch to another virtual switch within same host.
NETWORK POLICIES SUPPORTED BY VSPHERE STANDARD SWITCH
- Virtual Switch Tagging
- Virtual Guest Tagging
- External Switch Tagging
- Traffic Shaping
- IP based NIC Teaming
- MAC Based NIC Teaming
- Port ID based NIC Teaming
- Security Policies like Promiscuous Mode, Forged Transmits
TYPE OF VIRTUAL SWITCHES
- vSphere Standard Switch : It’s a legacy switch and configured at each ESXi Host level
- vSphere Distributed Switch: It’s a distributed switch spans across multiple ESXi Hosts and configured at vCenter Level. It also provides centralized management for entire datacenter networking.
VIDEO TUTORIAL ON HOW TO CONFIGURE VSPHERE STANDARD SWITCH
Please share your feedback on blog posts by providing your valuable comments or rating. Your feedback will help me to improvise blogging content to be more effective and worth reading.
Keep Sharing, Keep Learning!!!