How to Configure a Private Network on CentOS

Introduction

When deploying a VPS with a private network, you need to configure the private IP addresses. The examples shown in this guide are IPv4, but Vultr supports both IPv4 and IPv6. Vultr also supports multiple VLANs over a single private network interface with 802.1q tags. You'll find your server's information on the information page under Settings > IPv4. In the example below, the public network address is 192.0.2.123, and the private network address is 10.10.10.3. You'll find configuration samples for your server by clicking "View our networking configuration tips and examples."

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Private Networking Notes:

• When you enable private networking, you may use any RFC1918 private address as long as there are no conflicts with your other instances. Valid addresses include:
  • 10.0.0.0/8
  • 172.16.0.0/12
  • 192.168.0.0/16
• Private IP addresses in the customer portal are suggestions. You are not required to use the suggested private IP addresses.
• Private networks can not communicate between locations, regardless of IP addressing. For example, server instances in Miami can not see private networks in Dallas.
• Private networks do not have DHCP, and you must manually manage your IP address space or install a DHCP server on your private network.
• For optimal performance, set the private network adapter MTU to 1450 when configuring the NIC at the OS level.
• We also have guides to configure multiple private networks.

CentOS 8

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.

TYPE="Ethernet" 
DEVICE="ens7" 
ONBOOT="yes" 
BOOTPROTO="none" 
IPADDR=10.10.10.3
PREFIX=16
MTU=1450

Restart the connection, or reboot.

# nmcli con load /etc/sysconfig/network-scripts/ifcfg-ens7
# nmcli con up 'System ens7'

CentOS 7 and CentOS 6

Edit /etc/sysconfig/network-scripts/ifcfg-eth1

# nano /etc/sysconfig/network-scripts/ifcfg-eth1

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

DEVICE=eth1
ONBOOT=yes
NM_CONTROLLED=no
BOOTPROTO=static
IPADDR=10.10.10.3
NETMASK=255.255.0.0
IPV6INIT=no
MTU=1450

Start the interface or reboot.

# ifup eth1