ubuntu 18.04 set static ip method

1. Preface##

This tutorial will demonstrate how to set the static fixed IP address of Ubuntu 16.04 Server and Ubuntu 18.04 Server.

2. Confirm the network card number you want to modify##

First confirm the number of the network card you want to modify, assuming your server has multiple network cards:

ubuntu1804:~$ ip addr

My server configuration is as follows:

1: lo:<LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: ens33:<BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
link/ether 00:0c:29:f1:b5:e1 brd ff:ff:ff:ff:ff:ff
inet 172.16.87.140/24 brd 172.16.87.255 scope global dynamic ens33
valid_lft 1500sec preferred_lft 1500sec
inet6 fe80::20c:29ff:fef1:b5e1/64 scope link
valid_lft forever preferred_lft forever

3. Default network card configuration file##

By default, the network uses DHCP

ubuntu1804:~$ cat /etc/netplan/50-cloud-init.yaml
The content of the configuration file is as follows

network:
 ethernets:
  ens33:
   dhcp4: yes
   addresses:[]

 version:2

4. Set static IP

The configuration file needs to be modified as follows:

ubuntu1804:~$ sudo vi /etc/netplan/50-cloud-init.yaml

Suppose that the IP address is changed to 192.168.1.100, the subnet mask is 24 bits or 255.255.255.0, the gateway is set to 192.168.1.1, DNS1: 223.5.5.5, DNS2: 223.6.6.6

network:
 ethernets:
  ens33:
   dhcp4: no
   addresses:[192.168.1.100/24]
   optional:true
   gateway4:192.168.1.1
   nameservers:
     addresses:[223.5.5.5,223.6.6.6]

 version:2

5. Apply new configuration##

ubuntu1804:~$ sudo netplan apply 

Use ip addr to check the new address

ubuntu1804:~$ ip addr 

6. Test network connectivity##

ubuntu1804:~$ ping 192.168.1.100