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Troubleshooting VMs Connectivity with vRealize Network Insight

Julienne_Phamby Julienne Pham

Things can be difficult when you don’t know where a network issue may be.

In today’s datacentre, the rapid need to deploy business applications in minutes is necessary to keep the business ahead of the game. It is even more crucial to keep security and rapid networking configuration in control. So, how can a network administrator get to the bottom of a network issue in a matter of seconds in this new cloud era?

Network Virtualization brings operational and management flexibility and simplicity, but adds a complexity to troubleshooting and pinpointing the root cause of a network issue.

The traditional way would be to check the network activity from vCenter on the ESX level on the physical nic card, and check the packet going on as you run the test. It is also necessary to check the physical network activities and compare with the virtual network traffic and deduce where the bottleneck is.

If now you need to cross check between VCs and multiple sites, how long will it take to figure out the configuration issue? The required information can be gathered on one search on vRealize Network Insight.

In this example, I am searching the first top 5 VMs with the highest number of dropping packets across my datacenter.

A. Simple Search

 i.e “top 5 VMs by Max Packet Drops”

In this view, you can quickly scan which VM has the maximum dropped packet at which period, and compare with the other VMs to eventually filter.


You can eventually expand the VM data.

B. VM View

On this view search, you can get:

  1. The VM timeline which you can use to return to a previous state at a point in time to correlate VM status between the past and the present.
  2. Key information related to the VM, like vSphere ESXi connectivity events and errors, which can impact the VM health.
  3. The VM Topology which gives you more insight on the VM network configuration.


The ESXi host of this VM had a network error triggered in the past related to dropping packets on the dvswitch, but not in the last 24h.


C. VM Metrics

On this pin, we have more information on the VM compute data.

In this graph, we notice that the Snapshot Size increased and dropped at the same time as the VM recorded dropping packets on the network. We can then deduce that we have a correlation with committing snapshot VM and network packets lost. We can also go back in time and evaluate if it is a recurring issue or not.


You can check all the other Search capabilities under Help > Properties.


Not all the search functions are listed, but you can get an idea of how you can quickly search and get the information you are looking for.

You can help yourself by saving a User-defined Event to alert you of any change related to your custom search result.

This is just one possible way to use vRealize Network Insight to achieve a quick analysis. You have more possibilities and indefinite ways to use the custom search function to set notifications, assess your application VM’s security for compliance, or monitor status changes of any objects collected by Network Insight.

So why don’t you start using it today and tell us what you think?

Julienne Pham is a Technical Solution Architect for the Professional Services Engineering team. She is specialised on SRM and core storage. Her focus is on VIO and BCDR space.

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