All About Virtual Standard Switch (vSS) in VMWare

Here you will find about Virtual Standard Switch (vSS)

Topics you will cover :

  1. Virtual Networking
  2. Network Adapters
  3. Virtual Standard Switches(vSS)
  4. vSS functionality
  5. Similarities Between pSwitch and vSwitch
  6. Types of vSwitches
  7. Virtual Switch ports
  8. What is a vLAN?
  9. MAC address changes
  10. Forged transmits

Q1. Explain Virtual Networking?

It is a building block of an IP network for virtual machines that seamlessly integrates with the existing physical server environment. Just like physical server environment needs its physical network for its connectivity with one another. Physical network environment require physical NIC and physical switches similarly virtual networking requires virtual NIC and virtual switches.

Connectivity concept between physical and virtual environment:- 

Generally you need a NIC card for network connectivity whether it’s a Server/ Printer/ Appliance/ Router. NIC card is responsible for connecting one hardware to another that are connected through a network ,lets take an example that you have an ESXi host in your environment/network and multiple virtual machines are hosted on that hosted on that host ,in this case you cannot have 25 to 30 NIC cards for each VM in your host to make these VMs connected to the rest of the network .Here the virtual switch role comes into place .Virtual switch is software based installed on the kernel of each ESXi host that have ports on it to connect the VMs. In a virtual switch there are multiple ports like 24, 51, 52 etc.that can be added and can also be deleted. The vSwitches is serviced by multiple physical NIC cards i.e 1 or 2 NIC cards. In this way a virtual network is communicated with a physical network.

Q2. How will you find the Network Adapters in vCenter server?

GO to host -> Configuration -> Network Adapters -> on the R.H.S. you can see MAC ID’s , Observed IP range (vLANs  observed by the NICs) etc. You can see the physical NICs and IP addresses assigned to the network adapters or physical NICs.

Q3. Explain vSS (Virtual Standard Switch) and its functionality ?

  1. vSS are logical objects that resides in the vmkernel of each ESXi host means it is a software reside inside the vmkernel in a host.
  2. Each VM has its virtual NIC connected to a virtual switch will have its own MAC address just like a physical NIC has its own MAC ID.
  3. vSS can bound to one or more physical network adapter or physical NICs.


vSS functionality :-

  1. Each vSS can contain one or more port groups that define the type of communication expected through the vSwitch.
  2. vSS operate at layer 2 and can provide vLAN tagging security, checksums and segmentation offload units.

Q4. Explain the difference between physical switch (pSwitch) and virtual switch (vSwitch)?

Difference Between Physical Switch (pSwitch) and Virtual Switch (vSwitch) :-

Virtual switches are different from physical switches:-

  1. Virtual switches cannot be connected to a virtual switch the way physical switches can do so.
  2. Virtual switch does not support spanning tree tree protocol.
  3. Virtual switches isolation prevents loops in the switching configuration.
  4. Forwarding table data is unique to each virtual switch.

Q5. Explain the types of virtual switches ?

  1. Internal Only :- Used for communicating between two virtual machines hosted on the same ESXi host and is isolated from the network ouside.IT has no physical NIC bound to it which means the virtual machines connected to the virtual switch has no way of communicating with the rest of the network.
  2. Single Adapter :- A virtual switch is bound to a single physical adapter or physical NIC that is used for communicating with the resources on the physical network.
  3. NIC Teaming :- a virtual switch is bound to two or more physical NICs  used to provide redundancy and bandwidth aggregation for communication with resources on the physical network.

Q6. How to add a physical NIC to a Virtual Standard Switch (vSS) for redundancy purpose?

GO to Host -> Configuration ->  Networking ->on the R.H.S. click on properties of vSwitch0  -> on Network Adapters tab ,you can add or remove NICs. You can add only if you have physical NICs available.

Q7. How to add a Virtual Standard Switch (vSS) for redundancy purpose at switch level?

GO to Host -> Configuration ->  Networking  ->on the R.H.S. click on add Networking Button upwards for redundancy purpose at switch level.

It will prompt you a window :

  1. Connection Type :- a) Virtual Machine

b) VMkernel

  1. Network Access :- Select a particular NIC that is not assigned let’s say NIC1 as NIC0 is already assigned.
  2. Port Group Properties:- Label Network : for example management network 2.

VLAN ID : from dropdown menu.

Use this port group for vMotion.

Use this port group for Fault Tolerance.

Use this port group for Management Network.

  1. IP Settings:- IP Address and Subnet Mask.   Next and finish.

The second virtual switch is used for redundancy purpose of the management N/W. if you fail to connect to the host from one management N/W with one IP, you can connect through another management N/W through another IP or 2nd interface.