Configuring Additional IPs in bridge mode on your virtual machines

On the OVHcloud API page, click on Login in the top right-hand corner. On the next page, enter your OVHcloud credentials.

Execute the following API call, indicating the internal server name (example: ns3956771.ip-169-254-10.eu):

After you've created the virtual machine and while it's powered off, right click the VM and click Edit settings.

Fold out Network Adapter 1, change the value in the MAC Address drop-down menu to Manual and enter the virtual MAC address created previously.

Now you can start the VM and proceed with the configuration steps, depending on the operating system installed.

CentOS, Rocky Linux 8/9, Alma Linux 8/9, etc.

By default, the virtual machine's network configuration file is located in /etc/sysconfig/network-scripts/.

Once logged into your virtual machine shell, run the following command to identify the name of your interface:

ip a

Then make a copy of the configuration file, so that you can go back at any time:

sudo cp /etc/sysconfig/network-scripts/ifcfg-eth0 /etc/sysconfig/network-scripts/ifcfg-eth0.bak

In the event of an error, you can go back to the beginning using the commands below:

sudo rm -f etc/sysconfig/network-scripts/ifcfg-eth0
sudo cp /etc/sysconfig/network-scripts/ifcfg-eth0.bak etc/sysconfig/network-scripts/ifcfg-eth0

You can then edit this file using the nmcli handler, replacing ADDITIONAL_IP and GATEWAY_IP with your own values.

• Add the IP address:

sudo nmcli connection modify interface_name IPv4.address ADDITIONAL_IP/32

• Add the Gateway:

sudo nmcli connection modify interface_name IPv4.gateway GATEWAY_IP

• Add a DNS server:

sudo nmcli connection modify interface_name IPv4.dns 213.186.33.99

• Change the configuration to manual:

sudo nmcli connection modify interface_name IPv4.method manual

• Make the configuration persistent:

sudo nmcli con mod interface_name connection.autoconnect true

• Reboot your network with the following command:

sudo nmcli device down interface_name;nmcli device up interface_name

For more information on nmcli, consult this page.

By default, the virtual machine's network configuration file is located in /etc/rc.conf.

Once you are connected to the shell of your virtual machine, run the following command to identify your interface name:

ifconfig

Next, make a copy of the configuration file, so that you can revert at any time:

sudo cp /etc/rc.conf /etc/rc.conf.bak

In case of a mistake, you will be able to revert the changes, using the commands below:

sudo rm -f /etc/rc.conf
sudo cp /etc/rc.conf.bak /etc/rc.conf

Edit the file so that it reflects the configuration below, replace ADDITIONAL_IP and GATEWAY_IP with your own values. In this example, the interface name is em0. Replace this value if it does not apply.

ifconfig_em0="inet ADDITIONAL_IP netmask 255.255.255.255 broadcast ADDITIONAL_IP"
static_routes="net1 net2"
route_net1="-net GATEWAY_IP/32 -interface em0"
route_net2="default GATEWAY_IP"

Save and close the file.
Next, edit or create the file /etc/resolv.conf and add this line.

nameserver 213.186.33.99

Save and close the file, then reboot your virtual machine.

First, disable cloud-init:

touch /etc/cloud/cloud.cfg.d/99-disable-network-config.cfg

Add this line to the 99-disable-network-config.cfg file:

network: {config: disabled}

Then create the network configuration file in /etc/netplan/ with the following command:

touch /etc/netplan/00-installer-config.yaml

Then apply these permissions on /etc/netplan:

cd /etc/netplan
sudo chmod 600 *.yaml

Run the following command to identify the name of your interface:

ip addr

Next, make a copy of the configuration file, so that you can revert at any time. For demonstration purposes, our file is called 00-installer-config.yaml:

sudo cp /etc/netplan/00-installer-config.yaml /etc/netplan/00-installer-config.yaml.bak

In case of a mistake, you will be able to revert the changes, using the commands below:

sudo rm -f /etc/netplan/00-installer-config.yaml
sudo cp /etc/netplan/00-installer-config.yaml.bak /etc/netplan/00-installer-config.yaml

Next, open the network configuration file:

sudo nano /etc/netplan/00-installer-config.yaml

Edit the file so that it reflects the configuration below, replace INTERFACE-NAME, ADDITIONAL_IP and GATEWAY_IP with your own values.

network:
  ethernets:
    INTERFACE-NAME:
      dhcp4: true
      addresses:
          - ADDITIONAL_IP/32
      nameservers:
          addresses:
              - 213.186.33.99   
      routes:
           - to: 0.0.0.0/0
             via: GATEWAY_IP
             on-link: true
  version: 2

network:
  ethernets:
    ens18:
      dhcp4: true
      addresses:
          - 192.0.2.1/32
      nameservers:
          addresses:
              - 213.186.33.99
      routes:
           - to: 0.0.0.0/0
             via: 203.0.113.254
             on-link: true
  version: 2

Save and close the file. You can test the configuration with the following command:

sudo netplan try

If it is correct, apply it using the following command:

sudo netplan apply

Before configuring your virtual machine, you need to create a virtual switch.

From the command line of your dedicated server, run the following command and note the name of the network adapter that contains the server's main IP address:

ipconfig /all

In the Hyper-V Manager, create a new virtual switch and set the connection type to External.

Select the adapter with the server’s IP, then tick the option Allow management operating system to share this network adapter.

Next, select the VM you wish to add the Additional IP to. Use the Hyper-V Manager to change the settings of the VM and shut it down.

Expand the network adapter in the left-hand menu and click on Advanced Features. Change the MAC address to Static, and enter the virtual MAC address for the Additional IP. Once you have entered these settings, press OK to apply the changes.

Next, start the VM and log in as an administrator, then go to the Control Panel's Network and Sharing Center. Click on Ethernet to open the settings and click on the Properties button to view the Ethernet Properties.

Select Internet Protocol Version 4 (TCP/IPv4), and then click on the Properties button.

In the IPv4 Properties window, select Use the following IP address. Enter the Additional IP into the IP address field, and enter 255.255.255.255 into the subnet mask.

Fill in your server’s gateway IP address in the appropriate field below and enter 213.186.33.99 into the Preferred DNS Server field.

Finally, click OK, and ignore the warning message about the gateway IP and the assigned IP not being in the same subnet.

After rebooting the server, the VM should be connected to the internet using the Additional IP.