In VMware Workstation by default we have an host-only network which connects the VM and the host. We can also create internal network/Virtual Machine/Guest OS only network, which means VMs can’t connect to internet or our real LAN, but the VMs in the same Virtual Network can still talk to each other, which is ideal for some special usages/cases like testing environment etc.
In Proxmox VE (PVE) we only have Bridge network by default, which means virtual machines are always in the same LAN as the host resides in.
We can manually create the virtual machine only internal network simply, here is how.
1 Login to PVE web gui
2 Navigate to Datacenter -> node name/cluster name -> System -> Network
3 Click on “Create” button, click on “Linux Bridge”
4 We only need to enter the desired IPv4/CIDR, and Comment information.
IPv4/CIDR: Desired IP range for VMs to use for internal only network
Comment: For ourselves to distinguish among different interfaces/networks
Gateway: Make sure leave this field empty!
5 Click on “Create” button to create the VMs only internal network
Note: If we see this line “Pending changes (Either reboot or use ‘Apply Configuration’ (needs ifupdown2) to activate)”, try to click on “Apply Configuration” button first, if doesn’t work, logon to Proxmox terminal directly or via “Shell” button from PVE web gui, or via SSH, install ifupdown2 with ” apt install ifupdown2″, then click on “Apply configuration”
- Make sure we assign correct Network Interface for VMs in order to utilize this VM internal only network
- Make sure we assign IP address manually on each VM within the VM internal network, since there is no DHCP server, VMs will not be able to talk with each other by magic, we need to assign static IP addresses for them, make sure it is within the the range of “IPv4/CIDR” which we configured on “Linux Bridge” from step 4