Sometimes it can be tricky to fully access the VMware ESXi server as well as all virtual machine consoles (MKS) as the ESXi has multiple VMkernel ports but can only accept one single default gateway.

This is especially the case if your ESXi servers are hosted in a provider environment and you have only a public IP address as an initial configuration. To get a better idea of the network setup, check out the following simple network diagram.

  • Internet Gateway has the ip address (don’t use that example, as it’s the Google dns)
  • ESXi Host has two vmkernel adapter: vmk0 and vmk1
  • ESXi Default Gateway is configured to use
  • LAN Subnet / 24
  • LAN Gateway to access other networks
  • Client Admin subnet is / 24

network diagram - static routes for VMware ESXi

If you access the ESXi Host using, so the public ip address all works fine:

  • vSphere Client access
  • vCenter access
  • vSphere Webclient access
  • import of virtual appliances
  • Console session to virtual machines

If you try to access the ESXi Host using from a system located in (client Admin network) likely no communication will work. 

The system within the network knows its way to but there is no route that helps the VMkernel port to find it’s way back. The ESXi system always tries to use the vmk0 adapter and the default gateway to reach the network and that obviously fails.

VMkernel network configuration

Depending on the routing situation, the ip connectivity or the way vCenter is accessing the ESXi hosts using the client admin system you might be able to use the vSphere client, vCenter or the Webclient to access and configure the ESXi hosts or start virtual machines but the console session or the import of virtual appliances fails due to network errors. Sometimes the console session is just black.

In that example, this can be real tricky if the VMware vCenter server is located within the network and accessing all ESXi hosts in the right way and your client is connected to vCenter from All seems fine until you try to open a VM console session or an import of an ova image fails while accessing the vmdk files.

What needs to be done is to add a route for the network using the router.

Let’s start step by step:

  1. Open a console to the ESXi or ESX host. For more information, see Using Tech Support Mode in ESXi 4.1 and ESXi 5.x (1017910) orTech Support Mode for Emergency Support (1003677).
  2. ESX 4.x and 5.0, run esxcfg-route -a
  3. ESX 5.1 or 6.x, run esxcli network ip route ipv4 add –gateway –network

Check out the VMware KB article for more information

If all went well, you should be able to fully access your ESXi hosts using vSphere client or vCenter without any limitation. Should you run a hosted ESXi with a public IP being accessible out of the wild wild internet, now it’s also possible to completely lockdown the ESXi on the vmk0 interface. Of course before you made sure that you can access all you need from within the LAN or a VPN.

To health check on your vSphere environment make sure you register for vSphere Health Analyzer here

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Use Case - Tamper-resistant Clinical Trials


Blockchain PoCs were unsuccessful due to complexity and lack of developers.

Still the goal of data immutability as well as client verification is a crucial. Furthermore, the system needs to be easy to use and operate (allowing backup, maintenance windows aso.).


immudb is running in different datacenters across the globe. All clinical trial information is stored in immudb either as transactions or the pdf documents as a whole.

Having that single source of truth with versioned, timestamped, and cryptographically verifiable records, enables a whole new way of transparency and trust.

Use Case - Finance


Store the source data, the decision and the rule base for financial support from governments timestamped, verifiable.

A very important functionality is the ability to compare the historic decision (based on the past rulebase) with the rulebase at a different date. Fully cryptographic verifiable Time Travel queries are required to be able to achieve that comparison.


While the source data, rulebase and the documented decision are stored in verifiable Blobs in immudb, the transaction is stored using the relational layer of immudb.

That allows the use of immudb’s time travel capabilities to retrieve verified historic data and recalculate with the most recent rulebase.

Use Case - eCommerce and NFT marketplace


No matter if it’s an eCommerce platform or NFT marketplace, the goals are similar:

  • High amount of transactions (potentially millions a second)
  • Ability to read and write multiple records within one transaction
  • prevent overwrite or updates on transactions
  • comply with regulations (PCI, GDPR, …)


immudb is typically scaled out using Hyperscaler (i. e. AWS, Google Cloud, Microsoft Azure) distributed across the Globe. Auditors are also distributed to track the verification proof over time. Additionally, the shop or marketplace applications store immudb cryptographic state information. That high level of integrity and tamper-evidence while maintaining a very high transaction speed is key for companies to chose immudb.

Use Case - IoT Sensor Data


IoT sensor data received by devices collecting environment data needs to be stored locally in a cryptographically verifiable manner until the data is transferred to a central datacenter. The data integrity needs to be verifiable at any given point in time and while in transit.


immudb runs embedded on the IoT device itself and is consistently audited by external probes. The data transfer to audit is minimal and works even with minimum bandwidth and unreliable connections.

Whenever the IoT devices are connected to a high bandwidth, the data transfer happens to a data center (large immudb deployment) and the source and destination date integrity is fully verified.

Use Case - DevOps Evidence


CI/CD and application build logs need to be stored auditable and tamper-evident.
A very high Performance is required as the system should not slow down any build process.
Scalability is key as billions of artifacts are expected within the next years.
Next to a possibility of integrity validation, data needs to be retrievable by pipeline job id or digital asset checksum.


As part of the CI/CD audit functionality, data is stored within immudb using the Key/Value functionality. Key is either the CI/CD job id (i. e. Jenkins or GitLab) or the checksum of the resulting build or container image.

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