This knowledgebase post is a Virtomize step by step guide about how to configure your networks properly.

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Proper network configuration

After setting up your cluster, you will be redirected to the Cluster Configuration page that shows you all discovered networks from this cluster, as well as general information about the cluster. All networks are marked with a yellow exclemation mark and should be checked for proper configuration.

Our software is not able to determine if a network is configured to be static or dynamic in it’s IP address propagation. By default, all networks are assumed to be dynamic.

Small excurse into IP configuration


Dynamic IP configuration uses a so called DHCP (Dynamic Host Configuration Protocol) server. This server manages IP addresses for the system in its network, instead of the systems itself. A new systems asks the DHCP server (using broadcast) for an IP address and the DHCP server answers the system (defined by its mac address of the used interface, also via broadcast) with a free IP address. Then the system configures itself to use this IP address.


Static IP configuration does not need an additional server for IP configuration management. The system itself has a predefined network interface configuration with the IP address given by the administrator (or virtomize software).

How to configure a network

Check every network for proper configuration.

If your network uses dynamic IP configuration, just save it, as the default is set to Automatic(DHCP).

If your network uses static IP configuration choose Static and set the following values:

  • Gateway - this is a server used to connect different networks (most often your network with the internet)
  • Domain Name Server (DNS) - this server is used to look up domain names
    • If you don’t have internal domain names (e.g. mycompany.local), you can use one of your internet service provider, google or some other big company (e.g. or
    • If you have internal domains then use your internal DNS server
  • Netmask (CIDR) - this is the definition of the network IP address range configured for this network on your routers in CIDR notation (e.g.
  • Virtomize IP-Range (CIDR) - this is a (sub)net of your Netmask, that is only used by Virtomize, to predict free IP addresses for static configurations
    • Virtomize is able to choose a free IP address for your system, even if it has a static configured network
    • This is done by using a seperate IP-Range where you have to make sure it is only used by Virtomize to prevent IP address conflicts
    • e.g. as a subnet of - new systems using this network will get an IP address from

Networks without internet access are a special case. Since virtomize needs at least one configured network to provide internet access to your virtual machine to be able to install the operating system. If you have networks without internet access, mark them as Local network. This allows our software to determine if a specific network configuration is viable for installing the virtual machine.


Sometimes things don’t work as expected and if this turns out to be true in your case this section may help you out.

I don’t know the network configuration


While configuring a network, I don’t know the specific values to configure the network properly.


The easiest way is to ask someone who should know, like your IT administrator or Head of IT.

If you are the IT administrator and don’t know the configuration, you can look up the configuration on your hypervisors network configuration.

An alternative is to lookup the configuration on the routers that are used to connect your hypervisor servers.

Not listed here?

If you have a problem thats missing here and belongs to this section please contact us.