Why Network Bridge field is empty while creating VM in proxmox? FIXED

[Helposoft Staff]

In Proxmox VE, a network bridge is essential for connecting virtual machines (VMs) to the physical network. If the "Bridge" field is empty when creating a VM, it means no bridge has been configured or recognized. Here's how you can set up and use a network bridge in Proxmox VE:

1. Set Up a Network Bridge​

First, you need to ensure that a network bridge is configured on your Proxmox VE node. This bridge will connect your VMs to the physical network through your network interface.

Using the Web Interface​

1. Log into Proxmox VE Web Interface.
2. Navigate to the "Datacenter" view, then select the node you want to configure.
3. Go to the "System" tab and click on "Network".
4. Add a Network Bridge:
   • Click on "Create" and select "Linux Bridge".
5. Configure the Bridge:
   • Bridge Name: Enter a name for the bridge, such as vmbr0.
   • Bridge Ports: Select the network interface you want to use for the bridge (e.g., eno1).
   • IP Address: Leave this blank if you don’t want the bridge to have its own IP address.
   • Netmask: Leave this blank as well if you’re not assigning an IP to the bridge itself.
   • Gateway: Leave this blank.
   • Autostart: Ensure this is checked if you want the bridge to start automatically on boot.
6. Save the Configuration:
   • Click "Add" to create the bridge.

Editing Configuration File (if necessary)​

If you prefer or need to configure the bridge manually, you can edit the network configuration file directly:

1. Access the Proxmox VE server via SSH or directly.
2. Open the Network Configuration File:
   

   nano /etc/network/interfaces

   
   or
   
   

   vi /etc/network/interfaces

   
   
   
3. Add the Bridge Configuration:
   Append the following configuration to the file, adjusting eno1 to your actual network interface and vmbr0 to your desired bridge name:
   
   

   auto vmbr0
   iface vmbr0 inet static
   address 159.100.XX.XX
   netmask 255.255.255.0
   gateway 159.100.XX.X
   bridge_ports eno1
   bridge_stp off
   bridge_fd 0

4. Save and Exit:
   • For nano, press Ctrl + X, then Y, and Enter.
   • For vi, press Esc, type :wq, and press Enter.
5. Restart the Networking Service:
   

   systemctl restart networking

   Alternatively, reboot the server:
   

   reboot

2. Assign the Bridge When Creating a VM​

1. Create a New VM:
   • Go to "Create VM" in the Proxmox web interface.
2. Network Configuration Step:
   • When you reach the "Network" step in the VM creation wizard, you should now see the bridge you configured (vmbr0) in the drop-down menu.
3. Select the Bridge:
   • Choose the bridge (e.g., vmbr0) to connect your VM to the network.
4. Complete the VM Creation:
   • Finish configuring the VM and complete the creation process.

3. Verify the Network Setup​

1. After the VM is created and started, verify its network configuration to ensure it’s connected through the bridge.
2. You can check the network interface of the VM and verify that it is receiving an IP address from the additional IPs you set up.

By setting up the network bridge correctly, you’ll ensure that your VMs can communicate with the external network using the additional IP addresses you configured.