ubuntu18 네트워크 인터페이스 카드 추가.

# 인터페이스 목록 확인.
ls /sys/class/net
# 인페이스 MAC 확인.
ifconfig -a
vi /etc/netplan/50-cloud-init.yaml

network:
    ethernets:
        enp0s31f6:
            addresses: [192.168.0.214/24]
            gateway4: 192.168.0.1
            nameservers:
              addresses: [168.126.63.1,8.8.8.8]
              #  search: [lesstif.com]
              #            dhcp4: yes
            dhcp4: no
#            optional: true
    version: 2
    
sudo netplan apply

network:
    ethernets:
        ens160:
            addresses:
                - 1.1.1.1/16
            #gateway4: 1.1.1.1
            nameservers:
                addresses:
                - 8.8.8.8
            routes:
            - to: 1.1.0.0/16
              via: 1.1.1.1
        
        ens33:
            addresses:
                - 1.1.1.1/26
            gateway4:   1.1.1.1

    version: 2