ifupdown

Configuring network interface on Ubuntu Server with ifupdown

Show all network interfaces on your server.

ip addr

Open the file and edit:

sudo nano /etc/network/interfaces

Default

auto lo
iface lo inet loopback

DHCP Configuration

auto enp3s0
allow-hotplug enp3s0
iface eth0 inet dhcp

Static interfaces with two local ip adresses.

# The primary network interface
auto enp1s0
iface enp1s0 inet static
 address 192.168.1.100
 netmask 255.255.255.0
 network 192.168.1.0
 broadcast 192.168.1.255
 gateway 192.168.1.1
 dns-nameservers 192.168.1.1 8.8.8.8

# The secondary network interface
iface enp1s0 inet static
 address 192.168.1.101
 netmask 255.255.255.0

Install bridge interfaces package.

sudo apt update
sudo apt install bridge-utils

Static bridge interfaces with two local ip adresses.

# Bridge between eth0 and eth1 or enp1s0 enp2s0
auto br0
iface br0 inet static
   address 10.0.0.1
   netmask 255.255.255.0
   network 10.0.0.0
   broadcast 10.0.0.255
   gateway 10.0.0.1
   dns-nameservers 10.0.0.1 8.8.8.8
   bridge_ports enp1s0 enp5s0 eno1
   bridge_stp off
   bridge_fd 0
   bridge_maxwait 0

# The secondary network interface
iface br0 inet static
 address 10.0.0.150
 netmask 255.255.255.0

Applying the Changes

restart interfaces

sudo systemctl restart networking