Q. Explain Port Groups in VMWare?

In vSphere 4.x we have Three types of port groups:

1. Virtual Machine.

2. VMKernal Port Group.

3. Service Console Port Group.

In vSphere 5.x we have two types of port groups:-

  1. Virtual Machine-> for passing VM traffic.
  2. VMKernal Port Group-> The VMKernal TCP/IP stack handles traffic for the following ESXi Servers: vSphere, VMotion, Fault Tolerance, iSCSI, NFS and host management.

In the VMotion port group label the N/W name carefully as it is case sensitive. If you fail to label the name of the N/W correctly the whole VMotion N/W fails.

Q. How to create an internal port group and for what purpose?


Go to Host -> configuration -> networking -> adding N/W on the right hand side -> without selecting any IP,VLAN ID, NIC Card through to it because it is for only internal purpose for the communication b/w one to another virtual machine connected through this internal port group. This is highly isolated.

Note: Generally we provide multiple uplinks or physical NIC’s through a VSS for redundancy purose or for load balancing.

What is VMHA and it’s Master/Slave, requirements of VMHA, Best practices for VMHA

Purpose: What is VMHA and it’s Master/Slave, requirements of VMHA, Best practices for VMHA


vSphere HA detects failures and provides rapid recovery for the vm’s running within the cluster. Core functionality of VMHA includes hosts and vm’s monitoring to minimize the downtime. When heartbeats cannot be detected HA must be turn on to use FT.

  1. Quickly bring back up the critical applications in the event of ESXi server failure.
  2. Decrease downtime and improve availability.
  3. Examples of business critical application
    1. Exchange / Email server
    2. Sql server /database
    3. Corporate file server and internet/web.
  1. VMHA monitors not only ESXi host failure but also OS failures
  2. Supports upto 32 ESXi Servers in a cluster
  3. VMHA protects all VM guests and all applications.
  4. VMHA checks not only management network and default gateway during hosts failure but it also checks the datastore heartbeat which was not there in vSphere 4.x but it is there in vSphere 5.x. In vSphere 4.x VMHA only checks management network and default gateway. Because it happens sometimes that the vms are still be serviced as the hosts is running that’s why the heartbeat of datastore has been checked in vSphere 5.x HA become a lot smarter.

Requirement of VMHA:

  • Shared storage for VMs running in HA cluster.
  • All hosts should have access to all VM N/W.
  • Can use DRS with VMHA or just VMHA only.
  • All hosts must be licensed for VMHA.
  • The cluster must be VMHA enabled.
  • All hosts must have a static IP address.

At least one management network N/W but best practice say two with two different IP address that enhance HA.


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.


What is VMware converter? Explain hot and cold migration?

Purpose:What is VMware converter? Explain hot and cold migration?


VMware converter is an application developed to migrate a source system into destination/target system. It converts and packages a machine or server into a new virtual machine that resides on an ESX/ESXi host. There are two types: A) P2V (Physical to virtual) B) V2V (Virtual to virtual)
A physical machine is converted into a virtual machine.
In V2V an existing VM running on one virtual platform is copied to a VM running on another virtual platform.


Cold Migration:

This occurs while source system is offline. That means physical source system is running but OS that is being cloned is inactive. A cold migration is being initiated by booting VMware converter from a disc. It is ideal for the systems like SQL Servers, Mail Servers/Exchange that have data regularly updated or altered.


Hot migration:

This occurs while the source system is in running state but few migrations are not recommended like AD domain controllers into a VM (This should be cloned during cold migrations). This works well with the systems where the local data remains static.
Note: During P2V all the physical drivers must be removed like PSP and firmware like other HBA card drivers cause in virtual platform it wide only consume CPU and Memory utilization with no reason.