How to Configure a Private Network on Fedora

Introduction

Vultr provides many flexible networking options for your cloud servers. In addition to the public network attached to every Vultr instance, you can configure up to five private networks per location. Private networks allow instances within a location to communicate without exposing the traffic to the public internet.

Please see the guide How to Configure a Private Network at Vultr for general information about Vultr's private network feature.

Private networks do not have DHCP. When deploying a Vultr cloud server with private networking, you must manually configure the private adapters or supply your own DHCP server. We provide network configuration examples for many popular operating systems, pre-configured for your instance's IP addresses. You can find these by navigating to the settings screen (1) for your server, then selecting IPv4 (2). Follow the networking configuration link (3) to view the configuration examples.

The configurations in the customer portal are your best source of specific information. Please see below for step-by-step instructions with generic examples.

Fedora 24 through 28

Verify that private networking is enabled for your cloud server. Your private network device is ens7. Your public network device is ens3.

Edit /etc/sysconfig/network-scripts/ifcfg-ens7

# nano /etc/sysconfig/network-scripts/ifcfg-ens7

Populate the file with the following configuration. Replace 10.10.10.3 with your IP address.

DEVICE=ens7
ONBOOT=yes
NM_CONTROLLED=no
BOOTPROTO=static
IPADDR=10.10.10.3
NETMASK=255.255.0.0
NOZEROCONF=yes
IPV6INIT=no
MTU=1450

Restart the connection, or reboot.

# systemctl restart network.service

Fedora 29 through 32

Verify that private networking is enabled for your cloud server. Your private network device is ens7. Your public network device is ens3.

Run the following commands. Replace 10.10.10.3 with your IP address.

# nmcli con add con-name private-net ifname ens7 type ethernet ipv4.method 'manual' ipv4.addresses '10.10.10.3/24' 802-3-ethernet.mtu 1450
# nmcli con up private-net

Optional: Use systemd-networkd

If you prefer to use systemd-networkd configuration instead of the default Fedora configuration, follow these steps. These instructions apply to Fedora 29 through 32.

1. Edit the public.network configuration.

   # nano /etc/systemd/network/public.network
   

   Add the following text.

   [Match]
   Name=ens3
   
   [Network]
   DHCP=yes
   

2. Save and exit the file.

3. Edit the private.network configuration.

   # nano /etc/systemd/network/private.network
   

   Add the following text. Replace 10.10.10.3 with your IP address.

   [Match]
   Name=ens7
   
   [Link]
   MTUBytes=1450
   
   [Network]
   Address=10.10.10.3/20
   

4. Save and exit the file.

5. Enable the resolver and make a symlink:

   # systemctl enable systemd-resolved
   # systemctl start systemd-resolved
   # rm -f /etc/resolv.conf
   # ln -s /run/systemd/resolve/resolv.conf /etc/resolv.conf
   

6. Enable and start the new network services.

   # systemctl enable systemd-networkd
   # systemctl start systemd-networkd
   

7. Disable NetworkManager and the network scripts.

   # systemctl disable NetworkManager
   # systemctl disable network
   

If the network fails to load, use the Vultr Web Console to make corrections. You may need to reboot in rare cases.

Manage Private Networks via API

The Vultr API offers several endpoints to manage private networks.