How to add a network bridge in Proxmox

[Helposoft Staff]

To add a network bridge in Proxmox and ensure your virtual machines can communicate with each other and the external network, you need to follow these steps:

Step 1: Create a Network Bridge in Proxmox​

1. Access Proxmox Web Interface:
   • Open your web browser and navigate to https://your_server_ip:8006 and log in.
2. Navigate to Network Configuration:
   • Go to Datacenter > your node > System > Network.
3. Add a Bridge:
   • Click on Create > Linux Bridge.
   • Configure the bridge with the following settings:
     • Name: Assign a name to the bridge (e.g., vmbr1).
     • Bridge Ports: Select the physical network interface you want to bridge (e.g., eth0).
     • IPv4/CIDR: (Optional) You can leave this blank or configure an IP address for management purposes.
     • Gateway: (Optional) Configure the gateway if necessary.
4. Save the Configuration:
   • Click Create and then Apply Configuration to save the changes.

Step 2: Configure the Bridge in the VM​

After creating the bridge in Proxmox, you need to configure the virtual machine to use this bridge.

1. Edit VM Network Settings:
   • Go to Datacenter > your node > your VM > Hardware.
   • Select the Network Device (usually net0) and click Edit.
   • Change the Bridge setting to the newly created bridge (e.g., vmbr1).
2. Save and Restart VM:
   • Save the settings and restart the VM to apply the changes.

Step 3: Configure Networking Inside the VM​

1. Access the VM:
   • Open the VM console from Proxmox or SSH into the VM if it has network access.
2. Edit Network Configuration:
   • In AlmaLinux, network configuration files are typically located in /etc/sysconfig/network-scripts/.
   • Edit the configuration file for your network interface (e.g., ifcfg-eth0).
3. Example Configuration for Static IP:
   

   sudo nano /etc/sysconfig/network-scripts/ifcfg-eth0

   
   
4. Update the file with your network settings:
   
   

   TYPE=Ethernet
   BOOTPROTO=static
   NAME=eth0
   DEVICE=eth0
   ONBOOT=yes
   IPADDR=your_vm_ip
   NETMASK=255.255.255.0
   GATEWAY=your_gateway_ip
   DNS1=8.8.8.8

5. Restart Network Service:
   

   sudo systemctl restart network

Example Configuration:​

• Proxmox Bridge (vmbr1) Settings:
  • Name: vmbr1
  • Bridge Ports: eth0
  • IPv4/CIDR: 192.168.1.1/24 (example for management)
  • Gateway: 192.168.1.254 (if needed)
• VM Network Configuration:
  

  TYPE=Ethernet
  BOOTPROTO=static
  NAME=eth0
  DEVICE=eth0
  ONBOOT=yes
  IPADDR=192.168.1.100
  NETMASK=255.255.255.0
  GATEWAY=192.168.1.254
  DNS1=8.8.8.8

Additional Notes:​

• DHCP: If you prefer to use DHCP, you can set BOOTPROTO=dhcp instead of static settings.
• Testing: Always test the network connectivity after making changes by pinging the gateway or an external IP.

By following these steps, you should have a working bridge in Proxmox and properly configured network settings for your AlmaLinux VM.