What is VMware NSX Guest Introspection and how is it configured?

VMware NSX provides powerful insight into network traffic and it allows administrators to handle traffic based on very powerful criteria, including the user that is logged into a resource. Now in VMware NSX 6.4, this insight has even been turned up a notch with the identity firewall. It can now distinguish between various network flows and the users that are behind those network flows. This provides some really interesting use cases such as being able to correctly implement microsegmentation on an RDSH server.  One of the mechanisms behind the powerful network abilities provided by VMware NSX is called guest introspection. What is VMware NSX guest introspection and how is it configured?  What are some of the requirements of the new capabilities with the identity firewall?

What is VMware NSX Guest Introspection and how is it configured?

In general, VMware NSX Guest Introspection offloads antivirus and anti-malware agent processing to a dedicated secure virtual appliance that is configured when Guest Introspection service is enabled at the cluster level.  However, it is also required when enabling the “identity at source” firewall functionality of the identity firewall.

Guest Introspection required for the user identity at source firewall capabilities

The process to install the Guest Introspection service on an ESXi cluster involves the following:

  • Installing Guest Introspection on Host Clusters
  • Installing the Guest Introspection Thin agent on Windows Virtual Machines
  • Additionally, if using Linux Virtual Machines, installing the guest introspection thin agent on Linux Virtual Machines.
  • The thin agent plays the role of detective and allows detecting the logon user id and IP address of the logon session coming from the user ID in question that we want to build the firewall policy around. This information is relayed to the NSX manager.

This is accomplished with guest introspection infrastructure. After the user logs in, VMware Tools Guest Introspection sees the login and sends the IP and user ID to the Service Virtual Machine (SVM). The SVM updates the NSX Manager with the IP and user ID details as well as the directory groups the user is a member of. The NSX Manager then applies the correct firewall policy based on these details.

To begin the installation of the guest introspection service deployment, navigate to Installation and Upgrade >> Service Deployments and click the green “+” sign.

Beginning-to-install-the-Guest-Introspection-service-deployment-for-the-clusterBeginning to install the Guest Introspection service deployment for the cluster

Select the Guest Introspection option.

Choose Guest Introspection services

Next, we select the cluster name of the cluster for which we want to enable the guest introspection service.

Select Clusters to deploy the Guest Introspection services to

We need to select storage and management network configuration for the SVM virtual machines that will be created to enable the guest introspection service.

Select the storage and management configuration for the Guest Introspection SVMs

Finally, review the options for the guest introspection service deployment.

Review the Guest Introspection SVM installation options

We will note several tasks that begin kicking off.  The Install agent task will begin on both hosts.

Agent installation begins on the hosts

In the Installation Status you will see the Enabling status listed while the service is deployed.

Status for Guest Introspection shows to be Enabling

Installation continues…

We see the installing process while SVMs are deployed

After a couple of minutes, the Guest Introspection installation will show as Succeeded.

Installation status shows succeeded for Guest Introspection service deployment

The special SVM virtual machine (security virtual machines) are created for every host in the cluster.

The SVM virtual machines are created as part of the guest introspection service deployment

In addition to installing the guest introspection service deployment on the vSphere ESXi cluster, we also need to make sure the guest introspection services are enabled within the virtual machines we want to work with guest introspection.  This is part of the VMware Tools package and is an option that needs to be configured as it is not turned on by default.  If VMware Tools is already install, we can modify the installation and include the VMCI Driver including the NSX File Introspection Driver and NSX Network Introspection Driver.

Installing VMware Tools Guest Introspection

You can verify the driver is loaded by typing fltmc at an administrator command prompt.  You should be able to see the vsepflt filter driver loaded.

Verifying the guest introspection driver is running in a virtual machine

Concluding Thoughts

The guest introspection service is an extremely important service that allows special insight into the network flows and other functionality of a virtual machine.  Hopefully this post – What is VMware NSX Guest Introspection and how is it configured? will help any who may have wondered what the service is and what it is used for.  The new NSX 6.4 identity firewall features depend on the guest introspection services running.

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Brandon Lee

Brandon Lee is the Senior Writer, Engineer and owner at Virtualizationhowto.com and has over two decades of experience in Information Technology. Having worked for numerous Fortune 500 companies as well as in various industries, Brandon has extensive experience in various IT segments and is a strong advocate for open source technologies. Brandon holds many industry certifications, loves the outdoors and spending time with family.

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